That theory doesn't hold up. The pancake theory does not account for the collapse of the core columns. The pancake theory requires five times the amount of time for the floors to pancacke their way to the ground. The pancake theory does not explain the pulverization of the cement or the horizontal ejection of steel and cement. The pancake theory does not explain the high temperatures required to melt the heavy steel structure. There were pools of molten steel in the wreckage.