Loss of structural integrity was likely a result of weakening caused by fires on the 5th to 7th floors. The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence. Further research, investigation, and analysis are needed to resolve this issue.
In other words: no reason.
The video clearly shows that it was not a collapse subsequent to a fire, but rather a controlled demolition: amongst the Internet investigators, the jury is in on this one. The investigation continues of WTC 1 and 2 (there's lots of interest), but the observation that there has never been a fire -induced collapse of large fire-protected steel building holds true for them too. If you could melt fire -protected hardened steel with kerosene, someone should tell the steel companies!
See our page Guardian.
This photo of
WTC 7 was taken after the fall of at
leat 1 biulding
Here you see the "font" of the building that was closest to the Twin Towers,
showing that there was no major damage to the structure.
This was a VERY solid biulding with a VERY WIDE footprint
World Trade Center building 7 was not hit by a plane.
it collapsed in its own footprint in free fall time.
The fires seen here appear to be very minimal,
and although we do not have an exact time of the photo,
it was at least after one building had collapsed
Building and the US Post office were
adjacent to WTC 7,
but for some reason they survived with minimal damage.
They were the same distance away from the towers
alos have to wonder how it could be hit by
part of the falling towers ?
Seeing how far away the towers were,
how could large chunks of the building be propelled blocks away ?
Original Article - Danish Press: WTC 7 "had to be destroyed" on 9/11
on the re-opening
of the new building 7,
journalist Mikkel Selin reports
"The 52 floor skyscraper World Trade Center nr. 7 was so badly damaged from the terror attack in 2001, that it had to be destroyed."
comments echo those of lease owner
Larry Silverstein who said in a 2003 PBS documentary
that on 9/11 he had made the decision to "pull" the building, a construction industry term meaning implode with explosives.
5:22 p.m. on
September 11th 2001, the 47 story building number 7 of the World
Trade Center Plaza came down in slightly over 8 seconds. The
building had not been hit by any plane, nor sustained any
significant damage from the "collapse" of the Twin Towers seven
hours earlier, nor was there any major fire in the building at the
time. The video clearly show that it was brought down as result of
a synchronized demolition.