The planes may have had explosives on them.

If there were bombs in the building, they would've exploded where they were planted. I don't think all of the bombs were planted exactly where the planes hit.

Most of the fuel from the plane burned up outside, meaning the jet exploded before it made contact with the tower? Or are you saying that most of the fuel, from the first jet, landed on the second tower?

Either way, after the planes crashed, the buildings melted. They were constructed using some sort of technique involving the entire building (inside and out) to be threaded with steel. They got hot, one floor toppled onto the other, finally they came straight down. And you didn't see explosions coming out the windows, those were people jumping.