Just out of curiosity I rechecked the first result on google search that subscribes to the official theory of pancake fall.
http://www.tms.org/pubs/journals/JOM/01 ... -0112.html
referring to figure 5 he says "As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell."
.Thats nonsense. He assumes the building started falling from the point where the most heavily burned floors were. IT WAS NOT LIKE THAT! I watched the fall from various sources frame by frame (on 25 frames per second videos) the fall started from the very top. Not from the heavily burned floors. When the top floor collapsed (the one with the TV antena on top) nothing happened to the burned floors. I was very careful to watch when exactly the burned floors started falling, and I urge everyone to do the same and see for himself.
He also makes another mistake of not mentioning at all that as the steel floor joists expanded (because of heat), the grip at the angle clips should toughen, but that's a minor point anyway.