Frankly nobody want's to believe the simplest explication. The towers shouldn't have collapsed. But they did…
They didn't collapsed because squads of secret mossad ninjas planted tons of explosives.
They simply collapsed because the construction was shit (sorry extreme "card castle" design and construction done by the "lowest bidder").
And all the cover up is just there so that the insurance is payed to Shekelstein and for the US to save face, because fear of a giant scandal and litigation that lead to the death of thousands in the mind of the Establishment is FAR FAR WORSE than lying to the whole world on a few details…