Nyctohylophobia

MYTH The South Tower fell first because it was destroyed by planted explosives or beam weapons, etc.

Ringleader Mohamed Atta crashed American Airlines Flight 11 N334AA, a Boeing 767-200ER, into the North Tower at about 8:46 A.M. Marwan Al Shehhi rammed United Airlines Flight 175 N612UA, a Boeing 767-200ER, into the South Tower at about 9:03 A.M. The South Tower collapsed at 9:59 A.M. and the North Tower collapsed at 10:28 A.M. The South Tower and North Tower collapsed after about 56 and 102 minutes, respectively, and the North Tower lasted about 46 minutes longer than the South Tower.

Why did the South Tower collapse so much sooner than the North Tower? According to the National Institute of Standards and Technology (NIST) Federal Building and Fire Safety Investigation of the World Trade Center Disaster{1}:
"The time it took for each WTC tower to collapse was due primarily to the differences in structural damage, the time it took the fires to travel from the impact area across the floors and core to critical locations, and the time it took to weaken the core and exterior columns. WTC 2 had asymmetric structural damage to the core including the severing of a corner core column and WTC 1 had more symmetrical damage. The fires in WTC 2 reached the east side of the building more quickly, within 10 to 20 minutes, than the 50 to 60 minutes it took the fires in WTC 1 to reach the south side."

{1} http://wtc.nist.gov/pubs/NCSTAR1-6ExecutiveSummary.pdf

Labels: Controlled Demolition, Twin Towers, WTC