"We made several modifications to the building as part of that renovation that we think helped save people's lives," says Lee Evey, who runs a billion-dollar project to renovate the Pentagon. They?ve been working on it since 1993. The first section was five days from being finished when the terrorists hit it with the plane.
The renovation project built strength into the 60-year-old limestone exterior with a web of steel beams and columns.
"You have these steel tubes and, again, they go from the first floor and go all the way to the fifth floor," says Evey. "We have everything bolted together in a strong steel matrix. It supports and encases the windows and provides tremendous additional strength to the wall."
When the plane hit at 350 miles an hour, the limestone layer shattered. But inside, those shards of stone were caught by a shield of cloth that lines the entire section of the building.
It is a special cloth that helps prevent masonry from fragmenting and turning into shrapnel. The cloth is also used to make bullet-resistant vests.
All of this, especially the steel, held up the third, fourth and fifth floors. They stayed up for 35 minutes. You can see them through the smoke, suspended over the hole gouged by the jet. Only after the evacuation did the heat melt the new steel away. Evey says that without the reconstruction, the floors might have collapsed immediately.