Marnix- The exterior of the building was damaged causing a redistribution of loads to the perimeter walls and columns. You also have fires which are burning for 7 hours. You are going to have a difference in thermal expansion between the core and exterior load bearing systems. The floors will begin to sag pulling inwards and bowing the perimeter columns and walls. As the loads are shifted, the whole structure becomes highly unstable and overloaded, leading to the collapse. Can I tell you it was a truss or column on the nth floor that was the straw that broke the camels back? No. I don't have specifics on floor plans, building materials, fire loacations, etc. I will be very interested to see the NIST report on WTC7 in 2006. I think then we will be able to have a much more detailed discussion. If you haven't seen their website, I suggest you check it out.

What I would like to know is how did so many people conspire to detonate #7. Were explosives placed during construction, before 9/11, on 9/11? How has nobody talked? Just imagine the magnitude of the operation. The only "evidence" is people saying they herd bombs going off and explosions. Again, do they expect it to just quietly begin to fall? Where is the paper trail? Who's responsible?