[Skullmeat]

Here we go: http://www.popularmechanics.com/military/amp49/1227842/

"Jet fuel cant melt steel beams."

No, but it can weaken them. Ever seen a hot piece of metal? Before it melts, it becomes soft and mallable. The beams supporting the WTC likely bent, and concrete, while having excellent compressive strength, has very little tensile strength. Thats why rebar is used in buildings. Without support the concrete simply buckled and broke apart. Domino effect from the floors crashing on top each other took hold, and the buildings came down.