COMMISSION MEMBERS

Thomas H. Kean, CHAIR

Lee H. Hamilton, VICE CHAIR

Richard Ben-Veniste

Bob Kerrey

Fred F. Fielding

John F. Lehman

Jamie S. Gorelick

Timothy J. Roemer

Slade Gorton

Philip Zelikow, Executive Director
Christopher A. Kojm, Deputy Executive Director
Daniel Marcus, General Counsel

Joanne M. Accolla Staff Assistant Alexis Albion Professional Staff Member Scott H. Allan, Jr. Counsel John A. Azzarello Counsel Caroline Barnes Professional Staff Member Warren Bass Professional Staff Member Ann M. Bennett Information Control Officer Mark S. Bittinger Professional Staff Member Madeleine Blot Counsel Antwion M. Blount Systems Engineer Sam Brinkley Professional Staff Member Geoffrey Scott Brown Research Assistant Daniel Byman Professional Staff Member Dianna Campagna Manager of Operations Samuel M.W. Caspersen Counsel Melissa A. Coffey Staff Assistant Lance Cole Consultant Marquittia L. Coleman Staff Assistant Marco A. Cordero Professional Staff Member Rajesh De Counsel George W. Delgrosso Investigator Gerald L. Dillingham Professional Staff Member Thomas E. Dowling Professional Staff Member Steven M. Dunne Deputy General Counsel Thomas R. Eldridge Counsel Alice Falk Editor John J. Farmer, Jr. Senior Counsel & Team Leader Alvin S. Felzenberg Deputy for Communications Lorry M. Fenner Professional Staff Member Susan Ginsburg Senior Counsel & Team Leader T. Graham Giusti Security Officer Nicole Marie Grandrimo Professional Staff Member Douglas N. Greenburg Counsel Barbara A. Grewe Senior Counsel, Special Projects Elinore Flynn Hartz Family Liaison Leonard R. Hawley Professional Staff Member L. Christine Healey Senior Counsel & Team Leader Karen Heitkotter Executive Secretary Walter T. Hempel II Professional Staff Member

C. Michael Hurley Senior Counsel & Team Leader Dana J. Hyde Counsel Professional John W. Ivicic Security Officer Michael N. Jacobson Counsel Hunter W. Jamerson Intern Bonnie D. Jenkins Counsel Reginald F. Johnson Staff Assistant R.William Johnstone Professional Staff Member Stephanie L. Kaplan Special Assistant & Managing Editor Miles L. Kara, Sr. Professional Staff Member Janice L. Kephart Counsel Hyon Kim Counsel Katarzyna Kozaczuk Financial Assistant Gordon Nathaniel Lederman Counsel Daniel J. Leopold Staff Assistant Sarah Webb Linden Professional Staff Member Douglas J. MacEachin Professional Staff Member & Team Leader Ernest R. May Senior Adviser Joseph McBride Intern James Miller Professional Staff Member Kelly Moore Professional Staff Member Charles M. Pereira Professional Staff Member John Raidt Professional Staff Member John Roth Senior Counsel & Team Leader Peter Rundlet Counsel Lloyd D. Salvetti Professional Staff Member Kevin J. Scheid Staff Member & Team Leader Kevin Shaeffer Professional Staff Member Tracy J. Shycoff Deputy for Administration & Finance Dietrich L. Snell Senior Counsel & Team Leader Jonathan DeWees Stull Communications Assistant Lisa Marie Sullivan Staff Assistant Quinn John Tamm, Jr. Professional Staff Member Catharine S.Taylor Staff Assistant Yoel Tobin Counsel Emily Landis Walker Professional Staff Member & Family Liaison Garth Wermter Senior IT Consultant Serena B.Wille Counsel Peter Yerkes Public Affairs Assistant

THE 9/11 COMMISSION REPORT

Final Report of the National Commission on Terrorist Attacks Upon the United States

EXECUTIVE SUMMARY

We present the narrative of this report and the recommendations that flow from it to the President of the United States, the United States Congress, and the American people for their consideration. Ten Commissioners-five Republicans and five Democrats chosen by elected leaders from our nation's capital at a time of great partisan division-have come together to present this report without dissent.

We have come together with a unity of purpose because our nation demands it. September 11, 2001, was a day of unprecedented shock and suffering in the history of the United States. The nation was unprepared.

A NATION TRANSFORMED

At 8:46 on the morning of September 11, 2001, the United States became a nation transformed.

An airliner traveling at hundreds of miles per hour and carrying some 10,000 gallons of jet fuel plowed into the North Tower of the World Trade Center in Lower Manhattan. At 9:03, a second airliner hit the South Tower. Fire and smoke billowed upward. Steel, glass, ash, and bodies fell below. The Twin Towers, where up to 50,000 people worked each day, both collapsed less than 90 minutes later.

At 9:37 that same morning, a third airliner slammed into the western face of the Pentagon. At 10:03, a fourth airliner crashed in a field in southern Pennsylvania. It had been aimed at the United States Capitol or the White House, and was forced down by heroic passengers armed with the knowledge that America was under attack.

More than 2,600 people died at the World Trade Center; 125 died at the Pentagon; 256 died on the four planes. The death toll surpassed that at Pearl Harbor in December 1941.

This immeasurable pain was inflicted by 19 young Arabs acting at the behest of Islamist extremists headquartered in distant Afghanistan. Some had been in the United States for more than a year, mixing with the rest of the population. Though four had training as pilots, most were not well-educated. Most spoke English poorly, some hardly at all. In groups of four or five, carrying with them only small knives, box cutters, and cans of Mace or pepper spray, they had hijacked the four planes and turned them into deadly guided missiles.

Why did they do this? How was the attack planned and conceived? How did the U.S. government fail to anticipate and prevent it? What can we do in the future to prevent similar acts of terrorism?

A Shock, Not a Surprise
The 9/11 attacks were a shock, but they should not have come as a surprise. Islamist extremists had given plenty of warning that they meant to kill Americans indiscriminately and in large numbers. Although Usama Bin Ladin himself would not emerge as a signal threat until the late 1990s, the threat of Islamist terrorism grew over the decade.

In February 1993, a group led by Ramzi Yousef tried to bring down the World Trade Center with a truck bomb. They killed six and wounded a thousand. Plans by Omar Abdel Rahman and others to blow up the Holland and Lincoln tunnels and other New York City landmarks were frustrated when the plotters were arrested. In October 1993, Somali tribesmen shot down U.S. helicopters, killing 18 and wounding 73 in an incident that came to be known as "Black Hawk down." Years later it would be learned that those Somali tribesmen had received help from al Qaeda.

In early 1995, police in Manila uncovered a plot by Ramzi Yousef to blow up a dozen U.S. airliners while they were flying over the Pacific. In November 1995, a car bomb exploded outside the office of the U.S. program manager for the Saudi National Guard in Riyadh, killing five Americans and two others. In June 1996, a truck bomb demolished the Khobar Towers apartment complex in Dhahran, Saudi Arabia, killing 19 U.S. servicemen and wounding hundreds. The attack was carried out primarily by Saudi Hezbollah, an organization that had received help from the government of Iran.

Until 1997, the U.S. intelligence community viewed Bin Ladin as a financier of terrorism, not as a terrorist leader. In February 1998, Usama Bin Ladin and four others issued a self-styled fatwa, publicly declaring that it was God's decree that every Muslim should try his utmost to kill any American, military or civilian, anywhere in the world, because of American "occupation" of Islam's holy places and aggression against Muslims.

In August 1998, Bin Ladin's group, al Qaeda, carried out near-simultaneous truck bomb attacks on the U.S. embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania. The attacks killed 224 people, including 12 Americans, and wounded thousands more.

In December 1999, Jordanian police foiled a plot to bomb hotels and other sites frequented by American tourists, and a U.S. Customs agent arrested Ahmed Ressam at the U.S. Canadian border as he was smuggling in explosives intended for an attack on Los Angeles International Airport.

In October 2000, an al Qaeda team in Aden, Yemen, used a motorboat filled with explosives to blow a hole in the side of a destroyer, the USS Cole, almost sinking the vessel and killing 17 American sailors.

The 9/11 attacks on the World Trade Center and the Pentagon were far more elaborate, precise, and destructive than any of these earlier assaults. But by September 2001, the executive branch of the U.S. government, the Congress, the news media, and the American public had received clear warning that Islamist terrorists meant to kill Americans in high numbers.

Who Is the Enemy?
Who is this enemy that created an organization capable of inflicting such horrific damage on the United States? We now know that these attacks were carried out by various groups of Islamist extremists. The 9/11 attack was driven by Usama Bin Ladin.

In the 1980s, young Muslims from around the world went to Afghanistan to join as volunteers in a jihad (or holy struggle) against the Soviet Union. A wealthy Saudi, Usama Bin Ladin, was one of them. Following the defeat of the Soviets in the late 1980s, Bin Ladin and others formed al Qaeda to mobilize jihads elsewhere.

The history, culture, and body of beliefs from which Bin Ladin shapes and spreads his message are largely unknown to many Americans. Seizing on symbols of Islam's past greatness, he promises to restore pride to people who consider themselves the victims of successive foreign masters. He uses cultural and religious allusions to the holy Qur'an and some of its interpreters. He appeals to people disoriented by cyclonic change as they confront modernity and globalization. His rhetoric selectively draws from multiple sources-Islam, history, and the region's political and economic malaise.

Bin Ladin also stresses grievances against the United States widely shared in the Muslim world. He inveighed against the presence of U.S. troops in Saudi Arabia, which is the home of Islam's holiest sites, and against other U.S. policies in the Middle East.

Upon this political and ideological foundation, Bin Ladin built over the course of a decade a dynamic and lethal organization. He built an infrastructure and organization in Afghanistan that could attract, train, and use recruits against ever more ambitious targets. He rallied new zealots and new money with each demonstration of al Qaeda's capability. He had forged a close alliance with the Taliban, a regime providing sanctuary for al Qaeda.

By September 11, 2001, al Qaeda possessed

• leaders able to evaluate, approve, and supervise the planning and direction of a major operation;
• a personnel system that could recruit candidates, indoctrinate them, vet them, and give them the necessary training;
• communications sufficient to enable planning and direction of operatives and those who would be helping them;
• an intelligence effort to gather required information and form assessments of enemy strengths and weaknesses;
• the ability to move people great distances; and
• the ability to raise and move the money necessary to finance an attack.

1998 to September 11, 2001
The August 1998 bombings of U.S. embassies in Kenya and Tanzania established al Qaeda as a potent adversary of the United States.

After launching cruise missile strikes against al Qaeda targets in Afghanistan and Sudan in retaliation for the embassy bombings, the Clinton administration applied diplomatic pressure to try to persuade the Taliban regime in Afghanistan to expel Bin Ladin. The administration also devised covert operations to use CIA-paid foreign agents to capture or kill Bin Ladin and his chief lieutenants. These actions did not stop Bin Ladin or dislodge al Qaeda from its sanctuary.

By late 1998 or early 1999, Bin Ladin and his advisers had agreed on an idea brought to them by Khalid Sheikh Mohammed (KSM) called the "planes operation." It would eventually culminate in the 9/11 attacks. Bin Ladin and his chief of operations, Mohammed Atef, occupied undisputed leadership positions atop al Qaeda. Within al Qaeda, they relied heavily on the ideas and enterprise of strong-willed field commanders, such as KSM, to carry out worldwide terrorist operations.

KSM claims that his original plot was even grander than those carried out on 9/11-ten planes would attack targets on both the East and West coasts of the United States. This plan was modified by Bin Ladin, KSM said, owing to its scale and complexity. Bin Ladin provided KSM with four initial operatives for suicide plane attacks within the United States, and in the fall of 1999 training for the attacks began. New recruits included four from a cell of expatriate Muslim extremists who had clustered together in Hamburg, Germany. One became the tactical commander of the operation in the United States: Mohamed Atta.

U.S. intelligence frequently picked up reports of attacks planned by al Qaeda. Working with foreign security services, the CIA broke up some al Qaeda cells. The core of Bin Ladin's organization nevertheless remained intact. In December 1999, news about the arrests of the terrorist cell in Jordan and the arrest of a terrorist at the U.S.-Canadian border became part of a "millennium alert." The government was galvanized, and the public was on alert for any possible attack.

In January 2000, the intense intelligence effort glimpsed and then lost sight of two operatives destined for the "planes operation." Spotted in Kuala Lumpur, the pair were lost passing through Bangkok. On January 15, 2000, they arrived in Los Angeles.

Because these two al Qaeda operatives had spent little time in the West and spoke little, if any, English, it is plausible that they or KSM would have tried to identify, in advance, a friendly contact in the United States. We explored suspicions about whether these two operatives had a support network of accomplices in the United States. The evidence is thin-simply not there for some cases, more worrisome in others.

We do know that soon after arriving in California, the two al Qaeda operatives sought out and found a group of ideologically like-minded Muslims with roots in Yemen and Saudi Arabia, individuals mainly associated with a young Yemeni and others who attended a mosque in San Diego. After a brief stay in Los Angeles about which we know little, the al Qaeda operatives lived openly in San Diego under their true names. They managed to avoid attracting much attention.

By the summer of 2000, three of the four Hamburg cell members had arrived on the East Coast of the United States and had begun pilot training. In early 2001, a fourth future hijacker pilot, Hani Hanjour, journeyed to Arizona with another operative, Nawaf al Hazmi, and conducted his refresher pilot training there. A number of al Qaeda operatives had spent time in Arizona during the 1980s and early 1990s.

During 2000, President Bill Clinton and his advisers renewed diplomatic efforts to get Bin Ladin expelled from Afghanistan. They also renewed secret efforts with some of the Taliban's opponents-the Northern Alliance-to get enough intelligence to attack Bin Ladin directly. Diplomatic efforts centered on the new military government in Pakistan, and they did not succeed. The efforts with the Northern Alliance revived an inconclusive and secret debate about whether the United States should take sides in Afghanistan's civil war and support the Taliban's enemies. The CIA also produced a plan to improve intelligence collection on al Qaeda, including the use of a small, unmanned airplane with a video camera, known as the Predator.

After the October 2000 attack on the USS Cole, evidence accumulated that it had been launched by al Qaeda operatives, but without confirmation that Bin Ladin had given the order. The Taliban had earlier been warned that it would be held responsible for another Bin Ladin attack on the United States. The CIA described its findings as a "preliminary judgment"; President Clinton and his chief advisers told us they were waiting for a conclusion before deciding whether to take military action. The military alternatives remained unappealing to them.

The transition to the new Bush administration in late 2000 and early 2001 took place with the Cole issue still pending. President George W. Bush and his chief advisers accepted that al Qaeda was responsible for the attack on the Cole, but did not like the options available for a response.

Bin Ladin's inference may well have been that attacks, at least at the level of the Cole, were risk free.

The Bush administration began developing a new strategy with the stated goal of eliminating the al Qaeda threat within three to five years.

During the spring and summer of 2001, U.S. intelligence agencies received a stream of warnings that al Qaeda planned, as one report put it, "something very, very, very big." Director of Central Intelligence George Tenet told us, "The system was blinking red."

Although Bin Ladin was determined to strike in the United States, as President Clinton had been told and President Bush was reminded in a Presidential Daily Brief article briefed to him in August 2001, the specific threat information pointed overseas. Numerous precautions were taken overseas. Domestic agencies were not effectively mobilized. The threat did not receive national media attention comparable to the millennium alert.

While the United States continued disruption efforts around the world, its emerging strategy to eliminate the al Qaeda threat was to include an enlarged covert action program in Afghanistan, as well as diplomatic strategies for Afghanistan and Pakistan. The process culminated during the summer of 2001 in a draft presidential directive and arguments about the Predator aircraft, which was soon to be deployed with a missile of its own, so that it might be used to attempt to kill Bin Ladin or his chief lieutenants. At a September 4 meeting, President Bush's chief advisers approved the draft directive of the strategy and endorsed the concept of arming the Predator. This directive on the al Qaeda strategy was awaiting President Bush's signature on September 11, 2001.

Though the "planes operation" was progressing, the plotters had problems of their own in 2001. Several possible participants dropped out; others could not gain entry into the United States (including one denial at a port of entry and visa denials not related to terrorism). One of the eventual pilots may have considered abandoning the planes operation. Zacarias Moussaoui, who showed up at a flight training school in Minnesota, may have been a candidate to replace him.

Some of the vulnerabilities of the plotters become clear in retrospect. Moussaoui aroused suspicion for seeking fast-track training on how to pilot large jet airliners. He was arrested on August 16, 2001, for violations of immigration regulations. In late August, officials in the intelligence community realized that the terrorists spotted in Southeast Asia in January 2000 had arrived in the United States.

These cases did not prompt urgent action. No one working on these late leads in the summer of 2001 connected them to the high level of threat reporting. In the words of one official, no analytic work foresaw the lightning that could connect the thundercloud to the ground.

As final preparations were under way during the summer of 2001, dissent emerged among al Qaeda leaders in Afghanistan over whether to proceed. The Taliban's chief, Mullah Omar, opposed attacking the United States. Although facing opposition from many of his senior lieutenants, Bin Ladin effectively overruled their objections, and the attacks went forward.

September 11, 2001
The day began with the 19 hijackers getting through a security checkpoint system that they had evidently analyzed and knew how to defeat. Their success rate in penetrating the system was 19 for 19.They took over the four flights, taking advantage of air crews and cockpits that were not prepared for the contingency of a suicide hijacking.

On 9/11, the defense of U.S. air space depended on close interaction between two federal agencies: the Federal Aviation Administration (FAA) and North American Aerospace Defense Command (NORAD). Existing protocols on 9/11 were unsuited in every respect for an attack in which hijacked planes were used as weapons.

What ensued was a hurried attempt to improvise a defense by civilians who had never handled a hijacked aircraft that attempted to disappear, and by a military unprepared for the transformation of commercial aircraft into weapons of mass destruction.

A shootdown authorization was not communicated to the NORAD air defense sector until 28 minutes after United 93 had crashed in Pennsylvania. Planes were scrambled, but ineffectively, as they did not know where to go or what targets they were to intercept. And once the shootdown order was given, it was not communicated to the pilots. In short, while leaders in Washington believed that the fighters circling above them had been instructed to "take out" hostile aircraft, the only orders actually conveyed to the pilots were to "ID type and tail."

Like the national defense, the emergency response on 9/11 was necessarily improvised.

In New York City, the Fire Department of New York, the New York Police Department, the Port Authority of New York and New Jersey, the building employees, and the occupants of the buildings did their best to cope with the effects of almost unimaginable events-unfolding furiously over 102 minutes. Casualties were nearly 100 percent at and above the impact zones and were very high among first responders who stayed in danger as they tried to save lives. Despite weaknesses in preparations for disaster, failure to achieve unified incident command, and inadequate communications among responding agencies, all but approximately one hundred of the thousands of civilians who worked below the impact zone escaped, often with help from the emergency responders.

At the Pentagon, while there were also problems of command and control, the emergency response was generally effective. The Incident Command System, a formalized management structure for emergency response in place in the National Capital Region, overcame the inherent complications of a response across local, state, and federal jurisdictions.

Operational Opportunities
We write with the benefit and handicap of hindsight. We are mindful of the danger of being unjust to men and women who made choices in conditions of uncertainty and in circumstances over which they often had little control.

Nonetheless, there were specific points of vulnerability in the plot and opportunities to disrupt it. Operational failures-opportunities that were not or could not be exploited by the organizations and systems of that time-included

• not watchlisting future hijackers Hazmi and Mihdhar, not trailing them after they traveled to Bangkok, and not informing the FBI about one future hijacker's U.S. visa or his companion's travel to the United States;
• not sharing information linking individuals in the Cole attack to Mihdhar;
• not taking adequate steps in time to find Mihdhar or Hazmi in the United States;
• not linking the arrest of Zacarias Moussaoui, described as interested in flight training for the purpose of using an airplane in a terrorist act, to the heightened indications of attack;
• not discovering false statements on visa applications;
• not recognizing passports manipulated in a fraudulent manner;
• not expanding no-fly lists to include names from terrorist watchlists;
• not searching airline passengers identified by the computer-based CAPPS screening system; and
• not hardening aircraft cockpit doors or taking other measures to prepare for the possibility of suicide hijackings.

GENERAL FINDINGS

Since the plotters were flexible and resourceful, we cannot know whether any single step or series of steps would have defeated them. What we can say with confidence is that none of the measures adopted by the U.S. government from 1998 to 2001 disturbed or even delayed the progress of the al Qaeda plot. Across the government, there were failures of imagination, policy, capabilities, and management.

Imagination
The most important failure was one of imagination. We do not believe leaders understood the gravity of the threat. The terrorist danger from Bin Ladin and al Qaeda was not a major topic for policy debate among the public, the media, or in the Congress. Indeed, it barely came up during the 2000 presidential campaign.

Al Qaeda's new brand of terrorism presented challenges to U.S. governmental institutions that they were not well-designed to meet. Though top officials all told us that they understood the danger, we believe there was uncertainty among them as to whether this was just a new and especially venomous version of the ordinary terrorist threat the United States had lived with for decades, or it was indeed radically new, posing a threat beyond any yet experienced.

As late as September 4, 2001, Richard Clarke, the White House staffer long responsible for counterterrorism policy coordination, asserted that the government had not yet made up its mind how to answer the question: "Is al Qida a big deal?"

A week later came the answer.

Policy
Terrorism was not the overriding national security concern for the U.S. government under either the Clinton or the pre-9/11 Bush administration.

The policy challenges were linked to this failure of imagination. Officials in both the Clinton and Bush administrations regarded a full U.S. invasion of Afghanistan as practically inconceivable before 9/11.

Capabilities
Before 9/11, the United States tried to solve the al Qaeda problem with the capabilities it had used in the last stages of the Cold War and its immediate aftermath. These capabilities were insufficient. Little was done to expand or reform them.

The CIA had minimal capacity to conduct paramilitary operations with its own personnel, and it did not seek a large-scale expansion of these capabilities before 9/11. The CIA also needed to improve its capability to collect intelligence from human agents.

At no point before 9/11 was the Department of Defense fully engaged in the mission of countering al Qaeda, even though this was perhaps the most dangerous foreign enemy threatening the United States.

America's homeland defenders faced outward. NORAD itself was barely able to retain any alert bases at all. Its planning scenarios occasionally considered the danger of hijacked aircraft being guided to American targets, but only aircraft that were coming from overseas.

The most serious weaknesses in agency capabilities were in the domestic arena. The FBI did not have the capability to link the collective knowledge of agents in the field to national priorities. Other domestic agencies deferred to the FBI.

FAA capabilities were weak. Any serious examination of the possibility of a suicide hijacking could have suggested changes to fix glaring vulnerabilities-expanding no-fly lists, searching passengers identified by the CAPPS screening system, deploying federal air marshals domestically, hardening cockpit doors, alerting air crews to a different kind of hijacking possibility than they had been trained to expect. Yet the FAA did not adjust either its own training or training with NORAD to take account of threats other than those experienced in the past.

Management
The missed opportunities to thwart the 9/11 plot were also symptoms of a broader inability to adapt the way government manages problems to the new challenges of the twenty-first century. Action officers should have been able to draw on all available knowledge about al Qaeda in the government. Management should have ensured that information was shared and duties were clearly assigned across agencies, and across the foreign-domestic divide.

There were also broader management issues with respect to how top leaders set priorities and allocated resources. For instance, on December 4, 1998, DCI Tenet issued a directive to several CIA officials and the DDCI for Community Management, stating: "We are at war. I want no resources or people spared in this effort, either inside CIA or the Community." The memorandum had little overall effect on mobilizing the CIA or the intelligence community. This episode indicates the limitations of the DCI's authority over the direction of the intelligence community, including agencies within the Department of Defense.

The U.S. government did not find a way of pooling intelligence and using it to guide the planning and assignment of responsibilities for joint operations involving entities as disparate as the CIA, the FBI, the State Department, the military, and the agencies involved in homeland security.

SPECIFIC FINDINGS

Unsuccessful Diplomacy
Beginning in February 1997, and through September 11, 2001, the U.S. government tried to use diplomatic pressure to persuade the Taliban regime in Afghanistan to stop being a sanctuary for al Qaeda, and to expel Bin Ladin to a country where he could face justice. These efforts included warnings and sanctions, but they all failed.

The U.S. government also pressed two successive Pakistani governments to demand that the Taliban cease providing a sanctuary for Bin Ladin and his organization and, failing that, to cut off their support for the Taliban. Before 9/11, the United States could not find a mix of incentives and pressure that would persuade Pakistan to reconsider its fundamental relationship with the Taliban.

From 1999 through early 2001, the United States pressed the United Arab Emirates, one of the Taliban's only travel and financial outlets to the outside world, to break off ties and enforce sanctions, especially those related to air travel to Afghanistan. These efforts achieved little before 9/11.

Saudi Arabia has been a problematic ally in combating Islamic extremism. Before 9/11, the Saudi and U.S. governments did not fully share intelligence information or develop an adequate joint effort to track and disrupt the finances of the al Qaeda organization. On the other hand, government officials of Saudi Arabia at the highest levels worked closely with top U.S. officials in major initiatives to solve the Bin Ladin problem with diplomacy.

Lack of Military Options
In response to the request of policymakers, the military prepared an array of limited strike options for attacking Bin Ladin and his organization from May 1998 onward. When they briefed policymakers, the military presented both the pros and cons of those strike options and the associated risks. Policymakers expressed frustration with the range of options presented.

Following the August 20, 1998, missile strikes on al Qaeda targets in Afghanistan and Sudan, both senior military officials and policymakers placed great emphasis on actionable intelligence as the key factor in recommending or deciding to launch military action against Bin Ladin and his organization. They did not want to risk significant collateral damage, and they did not want to miss Bin Ladin and thus make the United States look weak while making Bin Ladin look strong. On three specific occasions in 1998-1999, intelligence was deemed credible enough to warrant planning for possible strikes to kill Bin Ladin. But in each case the strikes did not go forward, because senior policymakers did not regard the intelligence as sufficiently actionable to offset their assessment of the risks.

The Director of Central Intelligence, policymakers, and military officials expressed frustration with the lack of actionable intelligence. Some officials inside the Pentagon, including those in the special forces and the counterterrorism policy office, also expressed frustration with the lack of military action. The Bush administration began to develop new policies toward al Qaeda in 2001, but military plans did not change until after 9/11.

Problems within the Intelligence Community
The intelligence community struggled throughout the 1990s and up to 9/11 to collect intelligence on and analyze the phenomenon of transnational terrorism. The combination of an overwhelming number of priorities, flat budgets, an outmoded structure, and bureaucratic rivalries resulted in an insufficient response to this new challenge.

Many dedicated officers worked day and night for years to piece together the growing body of evidence on al Qaeda and to understand the threats. Yet, while there were many reports on Bin Laden and his growing al Qaeda organization, there was no comprehensive review of what the intelligence community knew and what it did not know, and what that meant. There was no National Intelligence Estimate on terrorism between 1995 and 9/11.

Before 9/11, no agency did more to attack al Qaeda than the CIA. But there were limits to what the CIA was able to achieve by disrupting terrorist activities abroad and by using proxies to try to capture Bin Ladin and his lieutenants in Afghanistan. CIA officers were aware of those limitations.

To put it simply, covert action was not a silver bullet. It was important to engage proxies in Afghanistan and to build various capabilities so that if an opportunity presented itself, the CIA could act on it. But for more than three years, through both the late Clinton and early Bush administrations, the CIA relied on proxy forces, and there was growing frustration within the CIA's Counterterrorist Center and in the National Security Council staff with the lack of results. The development of the Predator and the push to aid the Northern Alliance were products of this frustration.

Problems in the FBI
From the time of the first World Trade Center attack in 1993, FBI and Department of Justice leadership in Washington and New York became increasingly concerned about the terrorist threat from Islamist extremists to U.S. interests, both at home and abroad. Throughout the 1990s, the FBI's counterterrorism efforts against international terrorist organizations included both intelligence and criminal investigations. The FBI's approach to investigations was case-specific, decentralized, and geared toward prosecution. Significant FBI resources were devoted to after-the-fact investigations of major terrorist attacks, resulting in several prosecutions.

The FBI attempted several reform efforts aimed at strengthening its ability to prevent such attacks, but these reform efforts failed to implement organization-wide institutional change. On September 11, 2001, the FBI was limited in several areas critical to an effective preventive counterterrorism strategy. Those working counterterrorism matters did so despite limited intelligence collection and strategic analysis capabilities, a limited capacity to share information both internally and externally, insufficient training, perceived legal barriers to sharing information, and inadequate resources.

Permeable Borders and Immigration Controls
There were opportunities for intelligence and law enforcement to exploit al Qaeda's travel vulnerabilities. Considered collectively, the 9/11 hijackers

• included known al Qaeda operatives who could have been watchlisted;
• presented passports manipulated in a fraudulent manner;
• presented passports with suspicious indicators of extremism;
• made detectable false statements on visa applications;
• made false statements to border officials to gain entry into the United States; and
• violated immigration laws while in the United States.

Neither the State Department's consular officers nor the Immigration and Naturalization Service's inspectors and agents were ever considered full partners in a national counterterrorism effort. Protecting borders was not a national security issue before 9/11.

Permeable Aviation Security
Hijackers studied publicly available materials on the aviation security system and used items that had less metal content than a handgun and were most likely permissible. Though two of the hijackers were on the U.S.TIPOFF terrorist watchlist, the FAA did not use TIPOFF data. The hijackers had to beat only one layer of security-the security checkpoint process. Even though several hijackers were selected for extra screening by the CAPPS system, this led only to greater scrutiny of their checked baggage. Once on board, the hijackers were faced with aircraft personnel who were trained to be nonconfrontational in the event of a hijacking.

Financing
The 9/11 attacks cost somewhere between $400,000 and $500,000 to execute. The operatives spent more than $270,000 in the United States. Additional expenses included travel to obtain passports and visas, travel to the United States, expenses incurred by the plot leader and facilitators outside the United States, and expenses incurred by the people selected to be hijackers who ultimately did not participate.

The conspiracy made extensive use of banks in the United States. The hijackers opened accounts in their own names, using passports and other identification documents. Their transactions were unremarkable and essentially invisible amid the billions of dollars flowing around the world every day.

To date, we have not been able to determine the origin of the money used for the 9/11 attacks. Al Qaeda had many sources of funding and a pre-9/11 annual budget estimated at $30 million. If a particular source of funds had dried up, al Qaeda could easily have found enough money elsewhere to fund the attack.

An Improvised Homeland Defense
The civilian and military defenders of the nation's airspace-FAA and NORAD-were unprepared for the attacks launched against them. Given that lack of preparedness, they attempted and failed to improvise an effective homeland defense against an unprecedented challenge.

The events of that morning do not reflect discredit on operational personnel. NORAD's Northeast Air Defense Sector personnel reached out for information and made the best judgments they could based on the information they received. Individual FAA controllers, facility managers, and command center managers were creative and agile in recommending a nationwide alert, ground-stopping local traffic, ordering all aircraft nationwide to land, and executing that unprecedented order flawlessly.

At more senior levels, communication was poor. Senior military and FAA leaders had no effective communication with each other. The chain of command did not function well. The President could not reach some senior officials. The Secretary of Defense did not enter the chain of command until the morning's key events were over. Air National Guard units with different rules of engagement were scrambled without the knowledge of the President, NORAD, or the National Military Command Center.

Emergency Response
The civilians, firefighters, police officers, emergency medical technicians, and emergency management professionals exhibited steady determination and resolve under horrifying, overwhelming conditions on 9/11.Their actions saved lives and inspired a nation.

Effective decisionmaking in New York was hampered by problems in command and control and in internal communications. Within the Fire Department of New York, this was true for several reasons: the magnitude of the incident was unforeseen; commanders had difficulty communicating with their units; more units were actually dispatched than were ordered by the chiefs; some units self-dispatched; and once units arrived at the World Trade Center, they were neither comprehensively accounted for nor coordinated. The Port Authority's response was hampered by the lack both of standard operating procedures and of radios capable of enabling multiple commands to respond to an incident in unified fashion. The New York Police Department, because of its history of mobilizing thousands of officers for major events requiring crowd control, had a technical radio capability and protocols more easily adapted to an incident of the magnitude of 9/11.

Congress
The Congress, like the executive branch, responded slowly to the rise of transnational terrorism as a threat to national security. The legislative branch adjusted little and did not restructure itself to address changing threats. Its attention to terrorism was episodic and splintered across several committees. The Congress gave little guidance to executive branch agencies on terrorism, did not reform them in any significant way to meet the threat, and did not systematically perform robust oversight to identify, address, and attempt to resolve the many problems in national security and domestic agencies that became apparent in the aftermath of 9/11.

So long as oversight is undermined by current congressional rules and resolutions, we believe the American people will not get the security they want and need. The United States needs a strong, stable, and capable congressional committee structure to give America's national intelligence agencies oversight, support, and leadership.

Are We Safer?
Since 9/11, the United States and its allies have killed or captured a majority of al Qaeda's leadership; toppled the Taliban, which gave al Qaeda sanctuary in Afghanistan; and severely damaged the organization. Yet terrorist attacks continue. Even as we have thwarted attacks, nearly everyone expects they will come. How can this be?

The problem is that al Qaeda represents an ideological movement, not a finite group of people. It initiates and inspires, even if it no longer directs. In this way it has transformed itself into a decentralized force. Bin Ladin may be limited in his ability to organize major attacks from his hideouts. Yet killing or capturing him, while extremely important, would not end terror. His message of inspiration to a new generation of terrorists would continue.

Because of offensive actions against al Qaeda since 9/11, and defensive actions to improve homeland security, we believe we are safer today. But we are not safe. We therefore make the following recommendations that we believe can make America safer and more secure.

RECOMMENDATIONS

Three years after 9/11, the national debate continues about how to protect our nation in this new era. We divide our recommendations into two basic parts: What to do, and how to do it.

WHAT TO DO? A GLOBAL STRATEGY

The enemy is not just "terrorism." It is the threat posed specifically by Islamist terrorism, by Bin Ladin and others who draw on a long tradition of extreme intolerance within a minority strain of Islam that does not distinguish politics from religion, and distorts both.

The enemy is not Islam, the great world faith, but a perversion of Islam. The enemy goes beyond al Qaeda to include the radical ideological movement, inspired in part by al Qaeda, that has spawned other terrorist groups and violence. Thus our strategy must match our means to two ends: dismantling the al Qaeda network and, in the long term, prevailing over the ideology that contributes to Islamist terrorism.

The first phase of our post-9/11 efforts rightly included military action to topple the Taliban and pursue al Qaeda. This work continues. But long-term success demands the use of all elements of national power: diplomacy, intelligence, covert action, law enforcement, economic policy, foreign aid, public diplomacy, and homeland defense. If we favor one tool while neglecting others, we leave ourselves vulnerable and weaken our national effort.

What should Americans expect from their government? The goal seems unlimited: Defeat terrorism anywhere in the world. But Americans have also been told to expect the worst: An attack is probably coming; it may be more devastating still.

Vague goals match an amorphous picture of the enemy. Al Qaeda and other groups are popularly described as being all over the world, adaptable, resilient, needing little higher-level organization, and capable of anything. It is an image of an omnipotent hydra of destruction. That image lowers expectations of government effectiveness.

It lowers them too far. Our report shows a determined and capable group of plotters. Yet the group was fragile and occasionally left vulnerable by the marginal, unstable people often attracted to such causes. The enemy made mistakes. The U.S. government was not able to capitalize on them.

No president can promise that a catastrophic attack like that of 9/11 will not happen again. But the American people are entitled to expect that officials will have realistic objectives, clear guidance, and effective organization. They are entitled to see standards for performance so they can judge, with the help of their elected representatives, whether the objectives are being met.

We propose a strategy with three dimensions: (1) attack terrorists and their organizations, (2) prevent the continued growth of Islamist terrorism, and (3) protect against and prepare for terrorist attacks.

Attack Terrorists and Their Organizations

• Root out sanctuaries.The U.S. government should identify and prioritize actual or potential terrorist sanctuaries and have realistic country or regional strategies for each, utilizing every element of national power and reaching out to countries that can help us.
• Strengthen long-term U.S. and international commitments to the future of Pakistan and Afghanistan.
• Confront problems with Saudi Arabia in the open and build a relationship beyond oil, a relationship that both sides can defend to their citizens and includes a shared commitment to reform.

Prevent the Continued Growth of Islamist Terrorism
In October 2003, Secretary of Defense Donald Rumsfeld asked if enough was being done "to fashion a broad integrated plan to stop the next generation of terrorists." As part of such a plan, the U.S. government should

• Define the message and stand as an example of moral leadership in the world. To Muslim parents, terrorists like Bin Ladin have nothing to offer their children but visions of violence and death. America and its friends have the advantage-our vision can offer a better future.
• Where Muslim governments, even those who are friends, do not offer opportunity, respect the rule of law, or tolerate differences, then the United States needs to stand for a better future.
• Communicate and defend American ideals in the Islamic world, through much stronger public diplomacy to reach more people, including students and leaders outside of government. Our efforts here should be as strong as they were in combating closed societies during the Cold War.
• Offer an agenda of opportunity that includes support for public education and economic openness.
• Develop a comprehensive coalition strategy against Islamist terrorism, using a flexible contact group of leading coalition governments and fashioning a common coalition approach on issues like the treatment of captured terrorists.
• Devote a maximum effort to the parallel task of countering the proliferation of weapons of mass destruction.
• Expect less from trying to dry up terrorist money and more from following the money for intelligence, as a tool to hunt terrorists, understand their networks, and disrupt their operations.

Protect against and Prepare for Terrorist Attacks

• Target terrorist travel, an intelligence and security strategy that the 9/11 story showed could be at least as powerful as the effort devoted to terrorist finance.
• Address problems of screening people with biometric identifiers across agencies and governments, including our border and transportation systems, by designing a comprehensive screening system that addresses common problems and sets common standards. As standards spread, this necessary and ambitious effort could dramatically strengthen the world's ability to intercept individuals who could pose catastrophic threats.
• Quickly complete a biometric entry-exit screening system, one that also speeds qualified travelers.
• Set standards for the issuance of birth certificates and sources of identification, such as driver's licenses.
• Develop strategies for neglected parts of our transportation security system. Since 9/11, about 90 percent of the nation's $5 billion annual investment in transportation security has gone to aviation, to fight the last war.
• In aviation, prevent arguments about a new computerized profiling system from delaying vital improvements in the "no-fly" and "automatic selectee" lists. Also, give priority to the improvement of checkpoint screening.
• Determine, with leadership from the President, guidelines for gathering and sharing information in the new security systems that are needed, guidelines that integrate safeguards for privacy and other essential liberties.
• Underscore that as government power necessarily expands in certain ways, the burden of retaining such powers remains on the executive to demonstrate the value of such powers and ensure adequate supervision of how they are used, including a new board to oversee the implementation of the guidelines needed for gathering and sharing information in these new security systems.
• Base federal funding for emergency preparedness solely on risks and vulnerabilities, putting New York City and Washington, D.C., at the top of the current list. Such assistance should not remain a program for general revenue sharing or pork-barrel spending.
• Make homeland security funding contingent on the adoption of an incident command system to strengthen teamwork in a crisis, including a regional approach. Allocate more radio spectrum and improve connectivity for public safety communications, and encourage widespread adoption of newly developed standards for private-sector emergency preparedness-since the private sector controls 85 percent of the nation's critical infrastructure.
  

HOW TO DO IT? A DIFFERENT WAY OF ORGANIZING GOVERNMENT

The strategy we have recommended is elaborate, even as presented here very briefly. To implement it will require a government better organized than the one that exists today, with its national security institutions designed half a century ago to win the Cold War. Americans should not settle for incremental, ad hoc adjustments to a system created a generation ago for a world that no longer exists.

Our detailed recommendations are designed to fit together. Their purpose is clear: to build unity of effort across the U.S. government. As one official now serving on the front lines overseas put it to us: "One fight, one team."

We call for unity of effort in five areas, beginning with unity of effort on the challenge of counterterrorism itself:

• unifying strategic intelligence and operational planning against Islamist terrorists across the foreign-domestic divide with a National Counterterrorism Center;
• unifying the intelligence community with a new National Intelligence Director;
• unifying the many participants in the counterterrorism effort and their knowledge in a network-based information sharing system that transcends traditional governmental boundaries;
• unifying and strengthening congressional oversight to improve quality and accountability; and
• strengthening the FBI and homeland defenders.

Unity of Effort: A National Counterterrorism Center
The 9/11 story teaches the value of integrating strategic intelligence from all sources into joint operational planning-with both dimensions spanning the foreign-domestic divide.

• In some ways, since 9/11, joint work has gotten better. The effort of fighting terrorism has flooded over many of the usual agency boundaries because of its sheer quantity and energy. Attitudes have changed. But the problems of coordination have multiplied. The Defense Department alone has three unified commands (SOCOM, CENTCOM, and NORTHCOM) that deal with terrorism as one of their principal concerns.
• Much of the public commentary about the 9/11 attacks has focused on "lost opportunities." Though characterized as problems of "watchlisting," "information sharing," or "connecting the dots," each of these labels is too narrow. They describe the symptoms, not the disease.
• Breaking the older mold of organization stovepiped purely in executive agencies, we propose a National Counterterrorism Center (NCTC) that would borrow the joint, unified command concept adopted in the 1980s by the American military in a civilian agency, combining the joint intelligence function alongside the operations work.
• The NCTC would build on the existing Terrorist Threat Integration Center and would replace it and other terrorism "fusion centers" within the government. The NCTC would become the authoritative knowledge bank, bringing information to bear on common plans. It should task collection requirements both inside and outside the United States.
• The NCTC should perform joint operational planning, assigning lead responsibilities to existing agencies and letting them direct the actual execution of the plans.
• Placed in the Executive Office of the President, headed by a Senate-confirmed official (with rank equal to the deputy head of a cabinet department) who reports to the National Intelligence Director, the NCTC would track implementation of plans. It would be able to influence the leadership and the budgets of the counterterrorism operating arms of the CIA, the FBI, and the departments of Defense and Homeland Security.
• The NCTC should not be a policymaking body. Its operations and planning should follow the policy direction of the president and the National Security Council.

Unity of Effort: A National Intelligence Director
Since long before 9/11-and continuing to this day-the intelligence community is not organized well for joint intelligence work. It does not employ common standards and practices in reporting intelligence or in training experts overseas and at home. The expensive national capabilities for collecting intelligence have divided management. The structures are too complex and too secret.

• The community's head-the Director of Central Intelligence-has at least three jobs: running the CIA, coordinating a 15-agency confederation, and being the intelligence analyst-in-chief to the president. No one person can do all these things.
• A new National Intelligence Director should be established with two main jobs: (1) to oversee national intelligence centers that combine experts from all the collection disciplines against common targets- like counterterrorism or nuclear proliferation; and (2) to oversee the agencies that contribute to the national intelligence program, a task that includes setting common standards for personnel and information technology.
• The national intelligence centers would be the unified commands of the intelligence world-a long-overdue reform for intelligence comparable to the 1986 Goldwater-Nichols law that reformed the organization of national defense. The home services-such as the CIA, DIA, NSA, and FBI-would organize, train, and equip the best intelligence professionals in the world, and would handle the execution of intelligence operations in the field.

PREFACE

We present the narrative of this report and the recommendations that flow from it to the President of the United States, the United States Congress, and the American people for their consideration. Ten Commissioners-five Republicans and five Democrats chosen by elected leaders from our nation's capital at a time of great partisan division-have come together to present this report without dissent.

We have come together with a unity of purpose because our nation demands it. September 11, 2001, was a day of unprecedented shock and suffering in the history of the United States. The nation was unprepared. How did this happen, and how can we avoid such tragedy again?

To answer these questions, the Congress and the President created the National Commission on Terrorist Attacks Upon the United States (Public Law 107-306, November 27, 2002).

Our mandate was sweeping. The law directed us to investigate "facts and circumstances relating to the terrorist attacks of September 11, 2001," including those relating to intelligence agencies, law enforcement agencies, diplomacy, immigration issues and border control, the flow of assets to terrorist organizations, commercial aviation, the role of congressional oversight and resource allocation, and other areas determined relevant by the Commission.

In pursuing our mandate, we have reviewed more than 2.5 million pages of documents and interviewed more than 1,200 individuals in ten countries. This included nearly every senior official from the current and previous administrations who had responsibility for topics covered in our mandate.

We have sought to be independent, impartial, thorough, and nonpartisan. From the outset, we have been committed to share as much of our investigation as we can with the American people. To that end, we held 19 days of hearings and took public testimony from 160 witnesses.

Our aim has not been to assign individual blame. Our aim has been to provide the fullest possible account of the events surrounding 9/11 and to identify lessons learned.

We learned about an enemy who is sophisticated, patient, disciplined, and lethal. The enemy rallies broad support in the Arab and Muslim world by demanding redress of political grievances, but its hostility toward us and our values is limitless. Its purpose is to rid the world of religious and political pluralism, the plebiscite, and equal rights for women. It makes no distinction between military and civilian targets. Collateral damage is not in its lexicon.

We learned that the institutions charged with protecting our borders, civil aviation, and national security did not understand how grave this threat could be, and did not adjust their policies, plans, and practices to deter or defeat it. We learned of fault lines within our government-between foreign and domestic intelligence, and between and within agencies. We learned of the pervasive problems of managing and sharing information across a large and unwieldy government that had been built in a different era to confront different dangers.

At the outset of our work, we said we were looking backward in order to look forward. We hope that the terrible losses chronicled in this report can create something positive-an America that is safer, stronger, and wiser. That September day, we came together as a nation. The test before us is to sustain that unity of purpose and meet the challenges now confronting us.

We need to design a balanced strategy for the long haul, to attack terrorists and prevent their ranks from swelling while at the same time protecting our country against future attacks. We have been forced to think about the way our government is organized. The massive departments and agencies that prevailed in the great struggles of the twentieth century must work together in new ways, so that all the instruments of national power can be combined. Congress needs dramatic change as well to strengthen oversight and focus accountability.

As we complete our final report, we want to begin by thanking our fellow Commissioners, whose dedication to this task has been profound. We have reasoned together over every page, and the report has benefited from this remarkable dialogue. We want to express our considerable respect for the intellect and judgment of our colleagues, as well as our great affection for them.

We want to thank the Commission staff. The dedicated professional staff, headed by Philip Zelikow, has contributed innumerable hours to the completion of this report, setting aside other important endeavors to take on this all-consuming assignment. They have conducted the exacting investigative work upon which the Commission has built. They have given good advice, and faithfully carried out our guidance. They have been superb.

We thank the Congress and the President. Executive branch agencies have searched records and produced a multitude of documents for us. We thank officials, past and present, who were generous with their time and provided us with insight. The PENTTBOM team at the FBI, the Director's Review Group at the CIA, and Inspectors General at the Department of Justice and the CIA provided great assistance. We owe a huge debt to their investigative labors, painstaking attention to detail, and readiness to share what they have learned. We have built on the work of several previous Commissions, and we thank the Congressional Joint Inquiry, whose fine work helped us get started. We thank the City of New York for assistance with documents and witnesses, and the Government Printing Office and W.W. Norton & Company for helping to get this report to the broad public.

We conclude this list of thanks by coming full circle: We thank the families of 9/11, whose persistence and dedication helped create the Commission. They have been with us each step of the way, as partners and witnesses. They know better than any of us the importance of the work we have undertaken.

We want to note what we have done, and not done. We have endeavored to provide the most complete account we can of the events of September 11, what happened and why. This final report is only a summary of what we have done, citing only a fraction of the sources we have consulted. But in an event of this scale, touching so many issues and organizations, we are conscious of our limits. We have not interviewed every knowledgeable person or found every relevant piece of paper. New information inevitably will come to light. We present this report as a foundation for a better understanding of a landmark in the history of our nation.

We have listened to scores of overwhelming personal tragedies and astounding acts of heroism and bravery. We have examined the staggering impact of the events of 9/11 on the American people and their amazing resilience and courage as they fought back. We have admired their determination to do their best to prevent another tragedy while preparing to respond if it becomes necessary. We emerge from this investigation with enormous sympathy for the victims and their loved ones, and with enhanced respect for the American people. We recognize the formidable challenges that lie ahead.

We also approach the task of recommendations with humility. We have made a limited number of them. We decided consciously to focus on recommendations we believe to be most important, whose implementation can make the greatest difference. We came into this process with strong opinions about what would work. All of us have had to pause, reflect, and sometimes change our minds as we studied these problems and considered the views of others. We hope our report will encourage our fellow citizens to study, reflect-and act.

Tuesday, September 11, 2001, dawned temperate and nearly cloudless in the eastern United States. Millions of men and women readied themselves for work. Some made their way to the Twin Towers, the signature structures of the World Trade Center complex in New York City. Others went to Arlington, Virginia, to the Pentagon. Across the Potomac River, the United States Congress was back in session. At the other end of Pennsylvania Avenue, people began to line up for a White House tour. In Sarasota, Florida, President George W. Bush went for an early morning run.

Boarding the Flights
Boston: American 11 and United 175. Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston's Logan International Airport.¹

When he checked in for his flight to Boston, Atta was selected by a computerized prescreening system known as CAPPS (Computer Assisted Passenger Prescreening System), created to identify passengers who should be subject to special security measures. Under security rules in place at the time, the only consequence of Atta's selection by CAPPS was that his checked bags were held off the plane until it was confirmed that he had boarded the aircraft. This did not hinder Atta's plans. ²

Atta and Omari arrived in Boston at 6:45. Seven minutes later, Atta apparently took a call from Marwan al Shehhi, a longtime colleague who was at another terminal at Logan Airport. They spoke for three minutes.³ It would be their final conversation.

Between 6:45 and 7:40, Atta and Omari, along with Satam al Suqami, Wail al Shehri, and Waleed al Shehri, checked in and boarded American Airlines Flight 11, bound for Los Angeles. The flight was scheduled to depart at 7:45.⁴

In another Logan terminal, Shehhi, joined by Fayez Banihammad, Mohand al Shehri, Ahmed al Ghamdi, and Hamza al Ghamdi, checked in for United Airlines Flight 175, also bound for Los Angeles. A couple of Shehhi's colleagues were obviously unused to travel; according to the United ticket agent, they had trouble understanding the standard security questions, and she had to go over them slowly until they gave the routine, reassuring answers.⁵ Their flight was scheduled to depart at 8:00.

The security checkpoints through which passengers, including Atta and his colleagues, gained access to the American 11 gate were operated by Globe Security under a contract with American Airlines. In a different terminal, the single checkpoint through which passengers for United 175 passed was controlled by United Airlines, which had contracted with Huntleigh USA to perform the screening.⁶

In passing through these checkpoints, each of the hijackers would have been screened by a walk-through metal detector calibrated to detect items with at least the metal content of a .22-caliber handgun. Anyone who might have set off that detector would have been screened with a hand wand-a procedure requiring the screener to identify the metal item or items that caused the alarm. In addition, an X-ray machine would have screened the hijackers' carry-on belongings. The screening was in place to identify and confiscate weapons and other items prohibited from being carried onto a commercial flight.⁷ None of the checkpoint supervisors recalled the hijackers or reported anything suspicious regarding their screening.⁸

While Atta had been selected by CAPPS in Portland, three members of his hijacking team-Suqami, Wail al Shehri, and Waleed al Shehri-were selected in Boston. Their selection affected only the handling of their checked bags, not their screening at the checkpoint. All five men cleared the checkpoint and made their way to the gate for American 11. Atta, Omari, and Suqami took their seats in business class (seats 8D, 8G, and 10B, respectively). The Shehri brothers had adjacent seats in row 2 (Wail in 2A,Waleed in 2B), in the first-class cabin. They boarded American 11 between 7:31 and 7:40. The aircraft pushed back from the gate at 7:40. ⁹

Shehhi and his team, none of whom had been selected by CAPPS, boarded United 175 between 7:23 and 7:28 (Banihammad in 2A, Shehri in 2B, Shehhi in 6C, Hamza al Ghamdi in 9C, and Ahmed al Ghamdi in 9D).Their aircraft pushed back from the gate just before 8:00.¹⁰

Washington Dulles: American 77. Hundreds of miles southwest of Boston, at Dulles International Airport in the Virginia suburbs of Washington, D.C., five more men were preparing to take their early morning flight. At 7:15, a pair of them, Khalid al Mihdhar and Majed Moqed, checked in at the American Airlines ticket counter for Flight 77, bound for Los Angeles. Within the next 20 minutes, they would be followed by Hani Hanjour and two brothers, Nawaf al Hazmi and Salem al Hazmi.¹¹

Hani Hanjour, Khalid al Mihdhar, and Majed Moqed were flagged by CAPPS. The Hazmi brothers were also selected for extra scrutiny by the air-line's customer service representative at the check-in counter. He did so because one of the brothers did not have photo identification nor could he understand English, and because the agent found both of the passengers to be suspicious. The only consequence of their selection was that their checked bags were held off the plane until it was confirmed that they had boarded the aircraft.¹²

All five hijackers passed through the Main Terminal's west security screening checkpoint; United Airlines, which was the responsible air carrier, had contracted out the work to Argenbright Security.¹³ The checkpoint featured closed-circuit television that recorded all passengers, including the hijackers, as they were screened. At 7:18, Mihdhar and Moqed entered the security checkpoint.

Mihdhar and Moqed placed their carry-on bags on the belt of the X-ray machine and proceeded through the first metal detector. Both set off the alarm, and they were directed to a second metal detector. Mihdhar did not trigger the alarm and was permitted through the checkpoint. After Moqed set it off, a screener wanded him. He passed this inspection.¹⁴

About 20 minutes later, at 7:35, another passenger for Flight 77, Hani Han-jour, placed two carry-on bags on the X-ray belt in the Main Terminal's west checkpoint, and proceeded, without alarm, through the metal detector. A short time later, Nawaf and Salem al Hazmi entered the same checkpoint. Salem al Hazmi cleared the metal detector and was permitted through; Nawaf al Hazmi set off the alarms for both the first and second metal detectors and was then hand-wanded before being passed. In addition, his over-the-shoulder carry-on bag was swiped by an explosive trace detector and then passed. The video footage indicates that he was carrying an unidentified item in his back pocket, clipped to its rim.¹⁵

When the local civil aviation security office of the Federal Aviation Administration (FAA) later investigated these security screening operations, the screeners recalled nothing out of the ordinary. They could not recall that any of the passengers they screened were CAPPS selectees. We asked a screening expert to review the videotape of the hand-wanding, and he found the quality of the screener's work to have been "marginal at best." The screener should have "resolved" what set off the alarm; and in the case of both Moqed and Hazmi, it was clear that he did not.¹⁶

At 7:50, Majed Moqed and Khalid al Mihdhar boarded the flight and were seated in 12A and 12B in coach. Hani Hanjour, assigned to seat 1B (first class), soon followed.The Hazmi brothers, sitting in 5E and 5F, joined Hanjour in the first-class cabin.¹⁷

Newark: United 93. Between 7:03 and 7:39, Saeed al Ghamdi, Ahmed al Nami, Ahmad al Haznawi, and Ziad Jarrah checked in at the United Airlines ticket counter for Flight 93, going to Los Angeles. Two checked bags; two did not. Haznawi was selected by CAPPS. His checked bag was screened for explosives and then loaded on the plane.¹⁸

The four men passed through the security checkpoint, owned by United Airlines and operated under contract by Argenbright Security. Like the checkpoints in Boston, it lacked closed-circuit television surveillance so there is no documentary evidence to indicate when the hijackers passed through the checkpoint, what alarms may have been triggered, or what security procedures were administered. The FAA interviewed the screeners later; none recalled anything unusual or suspicious.¹⁹

The four men boarded the plane between 7:39 and 7:48. All four had seats in the first-class cabin; their plane had no business-class section. Jarrah was in seat 1B, closest to the cockpit; Nami was in 3C, Ghamdi in 3D, and Haznawi in 6B.²⁰

The 19 men were aboard four transcontinental flights.²¹ They were planning to hijack these planes and turn them into large guided missiles, loaded with up to 11,400 gallons of jet fuel. By 8:00 A.M. on the morning of Tuesday, September 11, 2001, they had defeated all the security layers that America's civil aviation security system then had in place to prevent a hijacking.

The Hijacking of American 11
American Airlines Flight 11 provided nonstop service from Boston to Los Angeles. On September 11, Captain John Ogonowski and First Officer Thomas McGuinness piloted the Boeing 767. It carried its full capacity of nine flight attendants. Eighty-one passengers boarded the flight with them (including the five terrorists).²²

The plane took off at 7:59. Just before 8:14, it had climbed to 26,000 feet, not quite its initial assigned cruising altitude of 29,000 feet. All communications and flight profile data were normal. About this time the "Fasten Seatbelt" sign would usually have been turned off and the flight attendants would have begun preparing for cabin service.²³

At that same time, American 11 had its last routine communication with the ground when it acknowledged navigational instructions from the FAA's air traffic control (ATC) center in Boston. Sixteen seconds after that transmis-sion, ATC instructed the aircraft's pilots to climb to 35,000 feet. That message and all subsequent attempts to contact the flight were not acknowledged. From this and other evidence, we believe the hijacking began at 8:14 or shortly thereafter.²⁴

Reports from two flight attendants in the coach cabin, Betty Ong and Madeline "Amy" Sweeney, tell us most of what we know about how the hijacking happened. As it began, some of the hijackers-most likely Wail al Shehri and Waleed al Shehri, who were seated in row 2 in first class-stabbed the two unarmed flight attendants who would have been preparing for cabin service.²⁵

We do not know exactly how the hijackers gained access to the cockpit; FAA rules required that the doors remain closed and locked during flight. Ong speculated that they had "jammed their way" in. Perhaps the terrorists stabbed the flight attendants to get a cockpit key, to force one of them to open the cockpit door, or to lure the captain or first officer out of the cockpit. Or the flight attendants may just have been in their way.²⁶

At the same time or shortly thereafter, Atta-the only terrorist on board trained to fly a jet-would have moved to the cockpit from his business-class seat, possibly accompanied by Omari. As this was happening, passenger Daniel Lewin, who was seated in the row just behind Atta and Omari, was stabbed by one of the hijackers-probably Satam al Suqami, who was seated directly behind Lewin. Lewin had served four years as an officer in the Israeli military. He may have made an attempt to stop the hijackers in front of him, not realizing that another was sitting behind him.²⁷

The hijackers quickly gained control and sprayed Mace, pepper spray, or some other irritant in the first-class cabin, in order to force the passengers and flight attendants toward the rear of the plane.They claimed they had a bomb.²⁸

About five minutes after the hijacking began, Betty Ong contacted the American Airlines Southeastern Reservations Office in Cary, North Carolina, via an AT&T airphone to report an emergency aboard the flight. This was the first of several occasions on 9/11 when flight attendants took action outside the scope of their training, which emphasized that in a hijacking, they were to communicate with the cockpit crew. The emergency call lasted approximately 25 minutes, as Ong calmly and professionally relayed information about events taking place aboard the airplane to authorities on the ground.²⁹

At 8:19, Ong reported: "The cockpit is not answering, somebody's stabbed in business class-and I think there's Mace-that we can't breathe-I don't know, I think we're getting hijacked." She then told of the stabbings of the two flight attendants.³⁰

At 8:21, one of the American employees receiving Ong's call in North Carolina, Nydia Gonzalez, alerted the American Airlines operations center in Fort Worth, Texas, reaching Craig Marquis, the manager on duty. Marquis soon realized this was an emergency and instructed the airline's dispatcher responsible for the flight to contact the cockpit. At 8:23, the dispatcher tried unsuccessfully to contact the aircraft. Six minutes later, the air traffic control specialist in American's operations center contacted the FAA's Boston Air Traffic Control Center about the flight. The center was already aware of the problem.³¹

Boston Center knew of a problem on the flight in part because just before 8:25 the hijackers had attempted to communicate with the passengers. The microphone was keyed, and immediately one of the hijackers said, "Nobody move. Everything will be okay. If you try to make any moves, you'll endanger yourself and the airplane. Just stay quiet." Air traffic controllers heard the transmission; Ong did not. The hijackers probably did not know how to operate the cockpit radio communication system correctly, and thus inadvertently broadcast their message over the air traffic control channel instead of the cabin public-address channel. Also at 8:25, and again at 8:29, Amy Sweeney got through to the American Flight Services Office in Boston but was cut off after she reported someone was hurt aboard the flight. Three minutes later, Sweeney was reconnected to the office and began relaying updates to the manager, Michael Woodward.³²

At 8:26, Ong reported that the plane was "flying erratically." A minute later, Flight 11 turned south. American also began getting identifications of the hijackers, as Ong and then Sweeney passed on some of the seat numbers of those who had gained unauthorized access to the cockpit.³³

Sweeney calmly reported on her line that the plane had been hijacked; a man in first class had his throat slashed; two flight attendants had been stabbed-one was seriously hurt and was on oxygen while the other's wounds seemed minor; a doctor had been requested; the flight attendants were unable to contact the cockpit; and there was a bomb in the cockpit. Sweeney told Woodward that she and Ong were trying to relay as much information as they could to people on the ground.³⁴

At 8:38, Ong told Gonzalez that the plane was flying erratically again. Around this time Sweeney told Woodward that the hijackers were Middle Easterners, naming three of their seat numbers. One spoke very little English and one spoke excellent English. The hijackers had gained entry to the cockpit, and she did not know how. The aircraft was in a rapid descent.³⁵

At 8:41, Sweeney told Woodward that passengers in coach were under the impression that there was a routine medical emergency in first class. Other flight attendants were busy at duties such as getting medical supplies while Ong and Sweeney were reporting the events.³⁶

At 8:41, in American's operations center, a colleague told Marquis that the air traffic controllers declared Flight 11 a hijacking and "think he's [American 11] headed toward Kennedy [airport in New York City].They're moving everybody out of the way. They seem to have him on a primary radar. They seem to think that he is descending."³⁷

At 8:44, Gonzalez reported losing phone contact with Ong. About this same time Sweeney reported to Woodward," Something is wrong. We are in a rapid descent . . . we are all over the place." Woodward asked Sweeney to look out the window to see if she could determine where they were. Sweeney responded: "We are flying low. We are flying very, very low. We are flying way too low." Seconds later she said, "Oh my God we are way too low." The phone call ended.³⁸

At 8:46:40, American 11 crashed into the North Tower of the World Trade Center in New York City.³⁹ All on board, along with an unknown number of people in the tower, were killed instantly.

The Hijacking of United 175
United Airlines Flight 175 was scheduled to depart for Los Angeles at 8:00. Captain Victor Saracini and First Officer Michael Horrocks piloted the Boeing 767, which had seven flight attendants. Fifty-six passengers boarded the flight.⁴⁰

United 175 pushed back from its gate at 7:58 and departed Logan Airport at 8:14. By 8:33, it had reached its assigned cruising altitude of 31,000 feet. The flight attendants would have begun their cabin service.⁴¹

The flight had taken off just as American 11 was being hijacked, and at 8:42 the United 175 flight crew completed their report on a "suspicious transmission" overheard from another plane (which turned out to have been Flight 11) just after takeoff. This was United 175's last communication with the ground.⁴²

The hijackers attacked sometime between 8:42 and 8:46.They used knives (as reported by two passengers and a flight attendant), Mace (reported by one passenger), and the threat of a bomb (reported by the same passenger). They stabbed members of the flight crew (reported by a flight attendant and one passenger). Both pilots had been killed (reported by one flight attendant).The eyewitness accounts came from calls made from the rear of the plane, from passengers originally seated further forward in the cabin, a sign that passengers and perhaps crew had been moved to the back of the aircraft. Given similarities to American 11 in hijacker seating and in eyewitness reports of tactics and weapons, as well as the contact between the presumed team leaders, Atta and Shehhi, we believe the tactics were similar on both flights.⁴³

The first operational evidence that something was abnormal on United 175 came at 8:47, when the aircraft changed beacon codes twice within a minute. At 8:51, the flight deviated from its assigned altitude, and a minute later New York air traffic controllers began repeatedly and unsuccessfully trying to contact it.⁴⁴

At 8:52, in Easton, Connecticut, a man named Lee Hanson received a phone call from his son Peter, a passenger on United 175. His son told him: "I think they've taken over the cockpit-An attendant has been stabbed- and someone else up front may have been killed. The plane is making strange moves. Call United Airlines-Tell them it's Flight 175, Boston to LA." Lee Hanson then called the Easton Police Department and relayed what he had heard.⁴⁵

Also at 8:52, a male flight attendant called a United office in San Francisco, reaching Marc Policastro. The flight attendant reported that the flight had been hijacked, both pilots had been killed, a flight attendant had been stabbed, and the hijackers were probably flying the plane. The call lasted about two minutes, after which Policastro and a colleague tried unsuccessfully to contact the flight.⁴⁶

At 8:58, the flight took a heading toward New York City.⁴⁷

At 8:59, Flight 175 passenger Brian David Sweeney tried to call his wife, Julie. He left a message on their home answering machine that the plane had been hijacked. He then called his mother, Louise Sweeney, told her the flight had been hijacked, and added that the passengers were thinking about storming the cockpit to take control of the plane away from the hijackers.⁴⁸

At 9:00, Lee Hanson received a second call from his son Peter:

It's getting bad, Dad-A stewardess was stabbed-They seem to have knives and Mace-They said they have a bomb-It's getting very bad on the plane-Passengers are throwing up and getting sick-The plane is making jerky movements-I don't think the pilot is flying the plane-I think we are going down-I think they intend to go to Chicago or someplace and fly into a building-Don't worry, Dad- If it happens, it'll be very fast-My God, my God.⁴⁹

The call ended abruptly. Lee Hanson had heard a woman scream just before it cut off. He turned on a television, and in her home so did Louise Sweeney. Both then saw the second aircraft hit the World Trade Center.⁵⁰

At 9:03:11, United Airlines Flight 175 struck the South Tower of the World Trade Center.⁵¹ All on board, along with an unknown number of people in the tower, were killed instantly.

The Hijacking of American 77
American Airlines Flight 77 was scheduled to depart from Washington Dulles for Los Angeles at 8:10. The aircraft was a Boeing 757 piloted by Captain Charles F. Burlingame and First Officer David Charlebois. There were four flight attendants. On September 11, the flight carried 58 passengers.⁵²

American 77 pushed back from its gate at 8:09 and took off at 8:20. At 8:46, the flight reached its assigned cruising altitude of 35,000 feet. Cabin service would have begun. At 8:51, American 77 transmitted its last routine radio communication. The hijacking began between 8:51 and 8:54. As on American 11 and United 175, the hijackers used knives (reported by one passenger) and moved all the passengers (and possibly crew) to the rear of the aircraft (reported by one flight attendant and one passenger). Unlike the earlier flights, the Flight 77 hijackers were reported by a passenger to have box cutters. Finally, a passenger reported that an announcement had been made by the "pilot" that the plane had been hijacked. Neither of the firsthand accounts mentioned any stabbings or the threat or use of either a bomb or Mace, though both witnesses began the flight in the first-class cabin.⁵³

At 8:54, the aircraft deviated from its assigned course, turning south. Two minutes later the transponder was turned off and even primary radar contact with the aircraft was lost. The Indianapolis Air Traffic Control Center repeatedly tried and failed to contact the aircraft. American Airlines dispatchers also tried, without success.⁵⁴

At 9:00, American Airlines Executive Vice President Gerard Arpey learned that communications had been lost with American 77.This was now the second American aircraft in trouble. He ordered all American Airlines flights in the Northeast that had not taken off to remain on the ground. Shortly before 9:10, suspecting that American 77 had been hijacked, American headquarters concluded that the second aircraft to hit the World Trade Center might have been Flight 77. After learning that United Airlines was missing a plane, American Airlines headquarters extended the ground stop nationwide.⁵⁵

At 9:12, Renee May called her mother, Nancy May, in Las Vegas. She said her flight was being hijacked by six individuals who had moved them to the rear of the plane. She asked her mother to alert American Airlines. Nancy May and her husband promptly did so.⁵⁶

At some point between 9:16 and 9:26, Barbara Olson called her husband, Ted Olson, the solicitor general of the United States. She reported that the flight had been hijacked, and the hijackers had knives and box cutters. She further indicated that the hijackers were not aware of her phone call, and that they had put all the passengers in the back of the plane. About a minute into the conversation, the call was cut off. Solicitor General Olson tried unsuccessfully to reach Attorney General John Ashcroft.⁵⁷

Shortly after the first call, Barbara Olson reached her husband again. She reported that the pilot had announced that the flight had been hijacked, and she asked her husband what she should tell the captain to do. Ted Olson asked for her location and she replied that the aircraft was then flying over houses. Another passenger told her they were traveling northeast. The Solicitor General then informed his wife of the two previous hijackings and crashes. She did not display signs of panic and did not indicate any awareness of an impending crash. At that point, the second call was cut off.⁵⁸

At 9:29, the autopilot on American 77 was disengaged; the aircraft was at 7,000 feet and approximately 38 miles west of the Pentagon.⁵⁹ At 9:32, controllers at the Dulles Terminal Radar Approach Control "observed a primary radar target tracking eastbound at a high rate of speed." This was later determined to have been Flight 77.

At 9:34, Ronald Reagan Washington National Airport advised the Secret Service of an unknown aircraft heading in the direction of the White House. American 77 was then 5 miles west-southwest of the Pentagon and began a 330-degree turn. At the end of the turn, it was descending through 2,200 feet, pointed toward the Pentagon and downtown Washington. The hijacker pilot then advanced the throttles to maximum power and dove toward the Pentagon.⁶⁰

At 9:37:46, American Airlines Flight 77 crashed into the Pentagon, traveling at approximately 530 miles per hour.⁶¹ All on board, as well as many civilian and military personnel in the building, were killed.

The Battle for United 93
At 8:42, United Airlines Flight 93 took off from Newark (New Jersey) Liberty International Airport bound for San Francisco. The aircraft was piloted by Captain Jason Dahl and First Officer Leroy Homer, and there were five flight attendants. Thirty-seven passengers, including the hijackers, boarded the plane. Scheduled to depart the gate at 8:00, the Boeing 757's takeoff was delayed because of the airport's typically heavy morning traffic.⁶²

The hijackers had planned to take flights scheduled to depart at 7:45 (American 11), 8:00 (United 175 and United 93), and 8:10 (American 77). Three of the flights had actually taken off within 10 to 15 minutes of their planned departure times. United 93 would ordinarily have taken off about 15 minutes after pulling away from the gate. When it left the ground at 8:42, the flight was running more than 25 minutes late.⁶³

As United 93 left Newark, the flight's crew members were unaware of the hijacking of American 11.Around 9:00, the FAA, American, and United were facing the staggering realization of apparent multiple hijackings. At 9:03, they would see another aircraft strike the World Trade Center. Crisis managers at the FAA and the airlines did not yet act to warn other aircraft.⁶⁴ At the same time, Boston Center realized that a message transmitted just before 8:25 by the hijacker pilot of American 11 included the phrase, "We have some planes."⁶⁵

No one at the FAA or the airlines that day had ever dealt with multiple hijackings. Such a plot had not been carried out anywhere in the world in more than 30 years, and never in the United States. As news of the hijackings filtered through the FAA and the airlines, it does not seem to have occurred to their leadership that they needed to alert other aircraft in the air that they too might be at risk.⁶⁶

United 175 was hijacked between 8:42 and 8:46, and awareness of that hijacking began to spread after 8:51. American 77 was hijacked between 8:51 and 8:54. By 9:00, FAA and airline officials began to comprehend that attackers were going after multiple aircraft. American Airlines' nationwide ground stop between 9:05 and 9:10 was followed by a United Airlines ground stop. FAA controllers at Boston Center, which had tracked the first two hijackings, requested at 9:07 that Herndon Command Center "get messages to airborne aircraft to increase security for the cockpit." There is no evidence that Herndon took such action. Boston Center immediately began speculating about other aircraft that might be in danger, leading them to worry about a transcontinental flight-Delta 1989-that in fact was not hijacked. At 9:19, the FAA's New England regional office called Herndon and asked that Cleveland Center advise Delta 1989 to use extra cockpit security.⁶⁷

Several FAA air traffic control officials told us it was the air carriers' responsibility to notify their planes of security problems. One senior FAA air traffic control manager said that it was simply not the FAA's place to order the airlines what to tell their pilots.⁶⁸ We believe such statements do not reflect an adequate appreciation of the FAA's responsibility for the safety and security of civil aviation.

The airlines bore responsibility, too. They were facing an escalating number of conflicting and, for the most part, erroneous reports about other flights, as well as a continuing lack of vital information from the FAA about the hijacked flights. We found no evidence, however, that American Airlines sent any cockpit warnings to its aircraft on 9/11. United's first decisive action to notify its airborne aircraft to take defensive action did not come until 9:19, when a United flight dispatcher, Ed Ballinger, took the initiative to begin transmitting warnings to his 16 transcontinental flights: "Beware any cockpit intrusion- Two a/c [aircraft] hit World Trade Center." One of the flights that received the warning was United 93. Because Ballinger was still responsible for his other flights as well as Flight 175, his warning message was not transmitted to Flight 93 until 9:23.⁶⁹

By all accounts, the first 46 minutes of Flight 93's cross-country trip proceeded routinely. Radio communications from the plane were normal. Heading, speed, and altitude ran according to plan. At 9:24, Ballinger's warning to United 93 was received in the cockpit. Within two minutes, at 9:26, the pilot, Jason Dahl, responded with a note of puzzlement: "Ed, confirm latest mssg plz-Jason."⁷⁰

The hijackers attacked at 9:28. While traveling 35,000 feet above eastern Ohio, United 93 suddenly dropped 700 feet. Eleven seconds into the descent, the FAA's air traffic control center in Cleveland received the first of two radio transmissions from the aircraft. During the first broadcast, the captain or first officer could be heard declaring "Mayday" amid the sounds of a physical struggle in the cockpit. The second radio transmission, 35 seconds later, indicated that the fight was continuing. The captain or first officer could be heard shouting:" Hey get out of here-get out of here-get out of here."⁷¹

On the morning of 9/11, there were only 37 passengers on United 93-33 in addition to the 4 hijackers. This was below the norm for Tuesday mornings during the summer of 2001. But there is no evidence that the hijackers manipulated passenger levels or purchased additional seats to facilitate their operation.⁷²

The terrorists who hijacked three other commercial flights on 9/11 operated in five-man teams. They initiated their cockpit takeover within 30 minutes of takeoff. On Flight 93, however, the takeover took place 46 minutes after takeoff and there were only four hijackers. The operative likely intended to round out the team for this flight, Mohamed al Kahtani, had been refused entry by a suspicious immigration inspector at Florida's Orlando International Airport in August.⁷³

Because several passengers on United 93 described three hijackers on the plane, not four, some have wondered whether one of the hijackers had been able to use the cockpit jump seat from the outset of the flight. FAA rules allow use of this seat by documented and approved individuals, usually air carrier or FAA personnel. We have found no evidence indicating that one of the hijackers, or anyone else, sat there on this flight. All the hijackers had assigned seats in first class, and they seem to have used them. We believe it is more likely that Jarrah, the crucial pilot-trained member of their team, remained seated and inconspicuous until after the cockpit was seized; and once inside, he would not have been visible to the passengers.⁷⁴

At 9:32, a hijacker, probably Jarrah, made or attempted to make the following announcement to the passengers of Flight 93:"Ladies and Gentlemen: Here the captain, please sit down keep remaining sitting. We have a bomb on board. So, sit." The flight data recorder (also recovered) indicates that Jarrah then instructed the plane's autopilot to turn the aircraft around and head east.⁷⁵

The cockpit voice recorder data indicate that a woman, most likely a flight attendant, was being held captive in the cockpit. She struggled with one of the hijackers who killed or otherwise silenced her.⁷⁶

Shortly thereafter, the passengers and flight crew began a series of calls from GTE airphones and cellular phones. These calls between family, friends, and colleagues took place until the end of the flight and provided those on the ground with firsthand accounts. They enabled the passengers to gain critical information, including the news that two aircraft had slammed into the World Trade Center.⁷⁷

At 9:39, the FAA's Cleveland Air Route Traffic Control Center overheard a second announcement indicating that there was a bomb on board, that the plane was returning to the airport, and that they should remain seated.⁷⁸ While it apparently was not heard by the passengers, this announcement, like those on Flight 11 and Flight 77, was intended to deceive them. Jarrah, like Atta earlier, may have inadvertently broadcast the message because he did not know how to operate the radio and the intercom. To our knowledge none of them had ever flown an actual airliner before.

At least two callers from the flight reported that the hijackers knew that passengers were making calls but did not seem to care. It is quite possible Jarrah knew of the success of the assault on the World Trade Center. He could have learned of this from messages being sent by United Airlines to the cockpits of its transcontinental flights, including Flight 93, warning of cockpit intrusion and telling of the New York attacks. But even without them, he would certainly have understood that the attacks on the World Trade Center would already have unfolded, given Flight 93's tardy departure from Newark. If Jarrah did know that the passengers were making calls, it might not have occurred to him that they were certain to learn what had happened in New York, thereby defeating his attempts at deception.⁷⁹

At least ten passengers and two crew members shared vital information with family, friends, colleagues, or others on the ground. All understood the plane had been hijacked. They said the hijackers wielded knives and claimed to have a bomb. The hijackers were wearing red bandanas, and they forced the passengers to the back of the aircraft.⁸⁰

Callers reported that a passenger had been stabbed and that two people were lying on the floor of the cabin, injured or dead-possibly the captain and first officer. One caller reported that a flight attendant had been killed.⁸¹

One of the callers from United 93 also reported that he thought the hijackers might possess a gun. But none of the other callers reported the presence of a firearm. One recipient of a call from the aircraft recounted specifically asking her caller whether the hijackers had guns. The passenger replied that he did not see one. No evidence of firearms or of their identifiable remains was found at the aircraft's crash site, and the cockpit voice recorder gives no indication of a gun being fired or mentioned at any time. We believe that if the hijackers had possessed a gun, they would have used it in the flight's last minutes as the passengers fought back.⁸²

Passengers on three flights reported the hijackers' claim of having a bomb. The FBI told us they found no trace of explosives at the crash sites. One of the passengers who mentioned a bomb expressed his belief that it was not real. Lacking any evidence that the hijackers attempted to smuggle such illegal items past the security screening checkpoints, we believe the bombs were probably fake.⁸³

During at least five of the passengers' phone calls, information was shared about the attacks that had occurred earlier that morning at the World Trade Center. Five calls described the intent of passengers and surviving crew members to revolt against the hijackers. According to one call, they voted on whether to rush the terrorists in an attempt to retake the plane. They decided, and acted.⁸⁴

At 9:57, the passenger assault began. Several passengers had terminated phone calls with loved ones in order to join the revolt. One of the callers ended her message as follows: "Everyone's running up to first class. I've got to go. Bye."⁸⁵

The cockpit voice recorder captured the sounds of the passenger assault muffled by the intervening cockpit door. Some family members who listened to the recording report that they can hear the voice of a loved one among the din. We cannot identify whose voices can be heard. But the assault was sustained.⁸⁶

In response, Jarrah immediately began to roll the airplane to the left and right, attempting to knock the passengers off balance. At 9:58:57, Jarrah told another hijacker in the cockpit to block the door. Jarrah continued to roll the airplane sharply left and right, but the assault continued. At 9:59:52, Jarrah changed tactics and pitched the nose of the airplane up and down to disrupt the assault. The recorder captured the sounds of loud thumps, crashes, shouts, and breaking glasses and plates. At 10:00:03, Jarrah stabilized the airplane.⁸⁷

Five seconds later, Jarrah asked, "Is that it? Shall we finish it off?" A hijacker responded, "No. Not yet. When they all come, we finish it off." The sounds of fighting continued outside the cockpit. Again, Jarrah pitched the nose of the aircraft up and down. At 10:00:26, a passenger in the background said, "In the cockpit. If we don't we'll die!" Sixteen seconds later, a passenger yelled, "Roll it!" Jarrah stopped the violent maneuvers at about 10:01:00 and said, "Allah is the greatest! Allah is the greatest!" He then asked another hijacker in the cock-pit, "Is that it? I mean, shall we put it down?" to which the other replied, "Yes, put it in it, and pull it down."⁸⁸

The passengers continued their assault and at 10:02:23, a hijacker said, "Pull it down! Pull it down!" The hijackers remained at the controls but must have judged that the passengers were only seconds from overcoming them. The airplane headed down; the control wheel was turned hard to the right. The airplane rolled onto its back, and one of the hijackers began shouting "Allah is the greatest. Allah is the greatest." With the sounds of the passenger counterattack continuing, the aircraft plowed into an empty field in Shanksville, Pennsylvania, at 580 miles per hour, about 20 minutes' flying time from Washington, D.C.⁸⁹

The FAA and NORAD
On 9/11, the defense of U.S. airspace depended on close interaction between two federal agencies: the FAA and the North American Aerospace Defense Command (NORAD).The most recent hijacking that involved U.S. air traffic controllers, FAA management, and military coordination had occurred in 1993.⁹⁰ In order to understand how the two agencies interacted eight years later, we will review their missions, command and control structures, and working relationship on the morning of 9/11.

FAA Mission and Structure. As of September 11, 2001, the FAA was mandated by law to regulate the safety and security of civil aviation. From an air traffic controller's perspective, that meant maintaining a safe distance between airborne aircraft.⁹¹

Many controllers work at the FAA's 22 Air Route Traffic Control Centers. They are grouped under regional offices and coordinate closely with the national Air Traff