Thing I noticed about the 9-11 controlled demolition

I hadn't noticed anyone making a big deal out of this so, my contribution to the 9-11 truth movement is to point out that a significant portion of the aluminium siding on one side of the North Tower stays up for about 10 seconds before collapsing. This shows to me both how strong the buildings were and how the floors just peeled away from the wall as if severed. They didn't "pancake" which should have pulled the siding and the walls down with it. In a video on Youtube at http://www.youtube.com/watch?v=A5kF9ldtgrc

you can see it standing from 6:47 to 6:57.