by B.J. Novitski

On September 11, when an American Airlines Boeing 757 crashed into the Pentagon, home of the U.S. Department of Defense (DoD), about 20,000 people were at work in this, the largest office building in the world. Yet according to the DoD casualty update on October 1, only 125 Pentagon employees were killed along with the 64 from the fated airliner.

That casualties were not much higher is attributed primarily to the fact that the portion of the building hit, the so-called "Wedge One," had been recently renovated. Contrary to initial reports, the reason for the low casualty rates was not that the offices were still vacant.

According to Pentagon renovation manager Lee Evey, about 80 percent of the Wedge One workers had returned to their offices. That sector of the building, therefore, potentially housed about 3500 workers that day. What saved so many lives, indisputably, is the structural stiffening Wedge One had undergone as part of a much needed, nearly completed, upgrade.

The exterior walls had been reinforced with steel beams and columns, bolted where they met at each floor. Some of these reinforced walls very near the point of impact remained in place for a half hour before collapsing, allowing uncounted hundreds to escape. "Had we not undertaken this effort," said Evey at a press briefing on September 15, "this could have been much, much worse."

Before September 11, the Pentagon was considered a fortress, shown here with the Potomac River and the Washington Monument in the background. Photo: U.S. Department of Defense A terrorist attack on the Pentagon in Washington D.C. on September 11 left a 100-foot (30-meter) hole but relatively few casualties. Photo: U.S. Department of Defense   Click on thumbnail images to view full-size pictures.