Reply #56: The upper section of WTC2 tilted because...

[Carefulplease]

The aircraft hit the South Tower on the south side where it punched a hole. One engine and one landing gear exited through the north-east corner. The core columns in the south-east corner were in the trajectory of the aircraft. The fires that were mainly located on the east isde caused truss floors to sag an pull on the east wall. This wall was seen to bow inwards long before the collapse. The upper section tilted progessively towards the east bowing wall and the south damaged wall. Those two walls and the south-east corner obviously failed first. That is why the upper section gained some angular momentum in the way that was observed.

Why some of that momentum was reduced while the upper block fell is anybodies guess. It is certainly no inexplicable. The rotational component of the momentum was obviously much smaller than the downward linear component. Jones's suggestion that gravity can not account for its progressive reduction is a red herring. It is obviously the inhomogeneity of the interactions between the upper and lower sections in the collapse zone that would be responsible -- whether or not explosives had been used -- for the application of some torque on the upper section. The event is just too chaotic for any definitive conclusion to be drawn. My guess is that since the upper block tilted towards the south and east, the south and east walls below offered some resistance to the falling upper block while only the floor connection resisted the other two walls that were also falling within the perimeter of the lower section.