Both towers fell faster than 10 storys per second. That was arguably no collapse; instead, there seemed to have been an internal vacuum, an implosion. What hit the earth caused unusual seismic signal less than that of a dumptruck (per Dr Judy Wood): No impact but instead a rebound, essentially as if an heavy weight had been suddenly removed from a waterbed not dropped onto it. This and the subsequent substantially absent debris indicated that the towers were disitegrated, “dustified” whilst in midair. Later, it was discovered that all 7 buildings having WTC prefix were destroyed, one completely disintegrated, another hollowed out inside down to ground-level. The most onerous evidence was the shocking lack of debris.