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Originally Posted by Chanda  The location of the damage causing the collapse is relevant. In order for a building to fall straight down into its own footprint at near freefall speed, the damage must be equally distributed throughout the building, and all supporting beams must fail simultaneously. NIST has yet to adequately explain the WTC7 collapse. |
The NIST has developed an extensive theory on the collapse of WTC 7 in which the collapse of a few core columns could have initiated a global collapse. The NIST has not finalized it but it still adequately explains the collapse.
http://wtc.nist.gov/pubs/WTC%20Part%...se%20Final.pdf