NIST believes that the Twin Towers each collapsed due to buckling of an exterior wall caused by sagging of floors.
caused by buckling of floor truss webs
caused by heating caused by fires and fireproofing damage
caused by debris impact and vibration caused by aircraft impact.
(All from NCSTAR 1-6)
caused by buckling of floor truss webs
caused by heating caused by fires and fireproofing damage
caused by debris impact and vibration caused by aircraft impact.
(All from NCSTAR 1-6)
The case of WTC1
NIST believes that the south wall was pulled in by the south trusses. This is strange because:
1. The impact was on the north side ... Read even more