Physical Features of the Towers' Destruction

• The buildings fell straight down, blowing outwards but not toppling.
• The buildings came down at nearly free-fall speed.
• Many witnesses reported sounds and sights of explosions.
• Virtually all the concrete was pulverized into very fine dust.
• Much of this dust, along with pieces of steel and aluminum, was blown out horizontally several hundred feet.
• Nearly all of the steel beams and columns came down in sections less than 80 feet long.

See Physical features of Towers' destruction