[cgbg]

The Building 7 issue is this—are there any other buildings ever, anywhere in the world, that fell in their own footprint due to debris from neighboring buildings?

I believe the answer is “no”—but I can be persuaded with a counter-example.

[woodbutcher1963]

The debris from the neighboring towers caught WTC7 on fire.
The fireman did not have any water to suppress the fire in #7.

WTC7 burned for over seven hours. The fire in the core of the building reached temperatures exceeding the point the steel lost its compression bending ratings. The weight of the building compressed the beams and they collapsed. Gravity did the rest.

I have not studied statics, mechanics and structural engineering since 1985. However, that is why building structures out of wood has an advantage in fire situations over steel.

[GregNH]

All high rise buildings have water tanks on the roof tops or very top floor to hold water for sprinkler systems. They were gravity fed when activated.