your proposition, you seemed to have eliminated the dynamic impact of the kinetic energy generated when the upper floors came falling down, accelarated by the gravity as it came falling.

how many floors by the way is on top of the burned floors?

granted there was explosives, but correct me if im wrong to have viewed the video images showned. that i don't seem to have seen any flash waves or burst of explosion that blew flames and debris further away from direct impact.

which means it was purely high heat by fire generated by jet fuel upon impact combined with burnt local building materials .... that caused the collapse.

anyway, i am just stating an opinionated observation here. maybe right maybe wrong... "caveat emptor"