Richard Gage of Architects and Engineers for 911 Truth - www.ae911truth.org - talks about the collapse of three high rise buildings in New York on the fateful morning of 9/11, killing almost three thousand people.
World Trade Center Building 7
Building 7 was destroyed in the manner of a classic implosion, falling suddenly, symmetrically, and at free-fall acceleration into its own footprint.
The Twin Towers
The Twin Towers were destroyed by waves of explosions that pulverized the building contents and hurled steel beams up to 600 ft in all directions.