It's my understanding that in order to drop a building in it's own "footprint" the center columns would have to be removed.
The thermite and/or thermate could have been used to cut the towers into pieces as they fell but the main explosion would have had to be massive.
I've seen pictures of the workers using blow torches to cut the remaining beams. Even those hot torches didn't them cut very fast.
What kind of explosive would be small enough to sneak into the building in advance yet powerfull enough to shake 110 story building and be recorded on a siesmic charts miles away?
What kind of explosive is strong enough to eliminate the 47 massive core columns of each tower and create the molten steel simmering for months afterwards?
Mini-hydrogen or nuclear ?
Did our own Government use a nuclear device on it's own citizens ?