I had what is I think an original thought. CTs are always claiming that there was molten metal in the WTC debris for weeks after the collapse, suggesting to them that thermite was used. While that's not very plausible for other reasons, I think that I can show that long-lasting underground hot spots cannot be due to thermite.
The reason that underground fires can burn for so long is the lack of oxygen, right? The fires can burn only as fast as fresh air can seep in, providing a necessary part of the chemical reaction that is fire.
I just checked, and the thermite reaction does not require oxygen from the air. What happens is that the oxygen atoms in iron oxide leave the iron and bond with the aluminum molecules, which releases lots of heat. No air required. This means that if there were any thermite reactions there, they would have happened immediately, then the heat would have quickly dissipated. Molten metal days later can't be due to thermite reactions.