"9-11: DISPLAY OF POLICE GUNS FOUND WITH MELTED CONCRETE IN THE RUINS OF THE WTC"
"CONCRETE MELTS AT 3000 DEGREES FAHRENHEIT, PROVING THAT TEMPERATURES INSIDE THE COLLAPSED WORLD TRADE CENTER HAD TO BE AT LEAST THAT HIGH."
So it couldn't have been the jet fuel!
See: Prop 202: 9/11 Revisited