Q: What are the official/mainstream explanations for the persisting heat at ground zero, and the inability to put out the fires for so long?
A: AFAIK, there is no official explanation. For every supporter of the official conspiracy though, you’ll receive on average 2 to 3 hypotheses involving some exotic chemical reaction between steel, concrete dust, gypsum wallboard, water and aluminum that somehow formed a self-assembling galvanothermitic kiln or somesuch, and in a stroke of luck, it did not also result in spontaneous biogenesis of space-faring fungi civilizations.
Q: What are the official/mainstream explanations for the persisting heat at ground zero
A: There isn’t one.
Q: Some conspiracy theory sources reason that this was because thermite makes it’s own oxygen and can be used under water
It is not a theory that thermite might have been involved, there is peer reviewed documentation that nano-thermite most defiantly was involved
For more information about this peer reviewed scientific article…
Thermitic Pyrotechnics in the WTC Made Simple: Three Points of Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe that Anyone Can Understand – A concise non-technical summary of three key points about recently documented unexploded pyrotechnics from the Twin Towers
Explosives Found in World Trade Center Dust: Scientists Discover Both Residues And Unignited Fragments Of High-Tech Metal Incendiaries In Debris From the Twin Towers – A non-technical guide to the newly published paper explaining the identification of nano-engineered explosive materials in dust from the Twin Towers