Originally Posted by **********

Gregory sir, what you are assuming is that the heat in these area only got as hot as the fuel might burn at. You are ignoring alot of other factors such as all of the other material that made up the offices and the building itself, the increased amount of airflow thanks to air intake (Heat rises and sucks up air from the hundreds of now blown-out windows), and most importantly, the flash point of all of the gasses generated by the burning items including evaporated but not yet burned jet fuel. These gases rise with heat and collect at the tops of the room. They continue to be heated by the fuel below until the the gases themselves, catch fire. This raises the tempurate way beyon 2000 degrees (Source: National Institute of Standards and Technology).

Thousands of degrees of heat, +
Damage by a 20 ton plane at 400 miles per hour, +
Thousands of tons of pressure..

yeah... those buildings feel down all by themselves... no controlled demolition needed.