No i'm sayign companies and public dont get to look around a military site for 30 years.
Anyway good mythbusters. 1000lbs of thermite and it didn't even cut through a car, with mavity on it's side. As you can see it turns to liquid and flows with mavity.
I don't think thermite was used, if anything was, in the WTC, but if it was it could be used in many forms for horizontal cutting including linear charges and hybrid penetrator charges.
That mythbusters video is lol tho, they just chuck ton of it down haphazardly and expect it to cut through a car, you could do it more effectively with a 100th of the amount and the right technique (look at some of the videos done by richard hammond).