Reply #10: From the NIST report [View All]

[mogster]

L.2.1 Damage from WTC 1 and WTC 2 Collapses
To place the events leading to the global collapse of WTC 7 into context, it is helpful to summarize the
events of September 11, 2001:

8:46 a.m. WTC 1 was struck by an aircraft
9:03 a.m. WTC 2 was struck by an aircraft
9:59 a.m. WTC 2 collapsed
10:28 a.m. WTC 1 collapsed
5:21 p.m. WTC 7 collapsed

After WTC 1 collapsed, the south face of WTC 7 was obscured by smoke, making direct observation of
damage from photographs or videos difficult or impossible. The source of the smoke is uncertain, as
large fires were burning in WTC 5 and WTC 6, as well as those noted below in WTC 7. The light but
prevalent winds from the northwest caused the smoke to rise on the leeward, or south, side of the
building. The following information about damage seen in WTC 7 was obtained from interviews of
people in or near the building:

After WTC 2 collapsed:
• Some south face glass panes were broken at lower lobby floors
• Dust covered the lobby areas at Floors 1 and 3
• Power was on in the building and phones were working
• No fires were observed

Reported close to time of WTC 1 collapse:

• East stair experienced an air pressure burst, filled with dust/smoke, lost lights
• West stair filled with dust/smoke, lost lights, swayed at Floors 29 through 30, and a crack was
felt (in the dark) on the stairwell wall between Floors 27 through 28 and Floors 29 through 30
• Floors 7 and 8 had no power, air was breathable but not clear

More (page 21 and onwards):
http://wtc.nist.gov/progress_report_june04/appendixl.pdf