No. The holes were not developed at melting pile of rubble like you imagine. They were dug out after the clean up and during the excavation for the new WTC foundation...which is why it was found years later. Well, yeah since they are glacial potholes there before the building existed. But no, not the way you are thinking. Are you clicking my links? Everything is explained. Page 10. Even pictures of the slurry as liquid before it was filled with dirt/dust. https://pbisotopes.ess.sunysb.edu/lig/Conferences/abstracts11/moss.pdf Along with old wood...again, not melted...or burned in that case.