WTC7, a solid steel 47-story building, spontaneously disintegrated and collapsed symmetrically into its footprint at near free-fall speed. This was due to small

WTC7, a solid steel 47-story building, spontaneously disintegrated and collapsed symmetrically into its footprint at near free-fall speed. This was due to small fires on the ground level, not the government. EDIT: small fires at ground level have caused perfect symmetric demolitions of many skyscrapers since WTC7. This is why small fires are now the preferred method of demolition.