When they go down like a stack of pancakes, they create a lot of dust from the fracturing concrete. I've seen this in a video from the conflict in the Middle East. A bomb or missile hit adjacent to the foundation of a multi-story building, and the building collapsed like a concertina. There is no way that mass was added in the collapse and you probably have a mistaken idea about how much was used to build the Towers. Constructed, they weighed 1.5 million tons (including 200,000 tons of steel and 425,000 cubic yards of concrete). Rubble is not a solid mass and will therefore be less dense than the original materials of construction, therefore bulking a larger volume for removal.

"Reports of explosions" are meaningless, as many violent sounds can be mistaken for explosions. What people hear is the shock wave overpressure, and pneumatic compression can create that as well as an explosion. A burst truck tire can sound very impressive. Guns make a similar report.

Your insults just demonstrate that you have no independent foundation for an explanation. I have Occam's Razor on my side.