The Ground Zero Fires
Were Not Conventional Fires
Here is a photograph showing the fires in the twin towers on 9/11:
The smoke rising from the towers is dark in color because it contains soot.
Here is a photograph showing Ground Zero following the collapses:
The fires at Ground Zero were oxygen starved, so the color of the smoke should be very dark. As you can see, this is not the case - the smoke is white. This video shot from a helicopter flying over the WTC wreckage on 15 September 2001 emphasizes the extent of the white smoke.
Also, the oxygen starved fires should have been relatively cool and easy to extinguish, but his was not the case:
The Ground Zero fires were not conventional fires.
Probable cause: thermite.
Thermal Hot Spots: Fingerprint
of a WTC Demolition
The 9/11 WTC Collapses: An Audio-Video Analysis
What Really Happened