How the Twin Towers Fell

Because the jets struck the World Trade Center Towers on the upper floors, the weight of the buildings caused their own collapse. As each concrete slab floor gave way, it smashed into the floor below. The massive downward crush of floors crashing, or pancaking, on floors, sent out enormous clouds of debris and smoke.

At 10:28 a.m., the north tower of the World Trade Center collapsed from top down, pancaking into dust.

Next: Ashes Cover the Skeleton of the Destroyed World Trade Center Towers >

September 11, 2001:
Destruction, Reconstruction, and Monuments