the planes hit the towers and were sitting pretty much in the center of each tower, burning the building from within. much of the support for the towers were based in the center of each tower where the burning happened to be occurring. the heat caused the steel to weaken, and collapse. since the weakening occurred from within the tower and in the center, there is no outside force to push it to any one side. the floors above the crash point collapse directly on top of the other floors due to the weakened structure, and because the rest of the tower wasn't built to withstand a third of itself collapsing on top of it, those top floors were able to rip down the tower's center taking it down with it.
please don't get another one of these arguments started, just leave it at this.
"Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour and it seems like a minute, that's relativity."
Xbox live gamertag: chazferrari689
Ride for Christ
Rage Against the Machine Cult
Classic Rock Cult