http://www.youtube.com/watch?v=Gud2ay4I9Mw
This is not a video of a "progressive collapse".
This is a building getting blown to bits. Trust your eyes people. Not lame explanations from experts that you don't even understand. They just "sound" good to you.
Ask your self whaet caused all those steel collumns to just disappear so quickly. Watch and keep watching. Look at the dust cloud and teh debris getting shot outward. Watch as the piledriving force gets obliterated, yt the building still continues to progressively collapse at lightning speed. As you watch the floors of the building get turned to dust and blasted outward, ask yourself what is driving the force of the collapse.
As mass from the top section is lost, you would expect the collapse to slow down. There is no reason for the collapse to progress to completion.
I would love you to show me a progressive collapse even remotely close to this. Remotely. It never happens.
The building that could take multiple 707 impacts turns to dust, yet we are supposed to believe this is completely understandable.
What is wrong with you people?