It’s the world’s largest low-rise office building. The entire U.S. Capitol building could fit inside any of the building’s five wedges. It has 6,500,000 square feet of office space (three times the floor space in the Empire State Building!), 7,754 windows and 17 1/2 miles of corridors. Yet, its spoke-and-ring design means it takes only about 7 minutes to walk between the furthest two points in the building.
The Pentagon is divided into five wedges, and the renovation project was going wedge by wedge when terrorists flew American Airlines Flight 77 into the Pentagon, Sept. 11, 2001, killing 189 people. The plane hit in Wedge 3, where renovations had just completed, but only about 800 out of the 4,500 people who normally would have been working there had moved back into their offices. And the new sprinkler system, extra structural support and blast-resistant windows helped to keep the building damage to a minimum, likely saving additional lives.
Col. Leslie Groves, an Army Corps of Engineer officer, took charge of the Pentagon’s construction in August 1941. He worked six days a week in his office in Washington. Then on Sundays, he would visit the project he felt most needed his personal attention. Groves later said of his time at the Pentagon that he was “hoping to get to a war theater so I could find a little peace.” Instead, he was assigned to direct the Manhattan Project – America’s effort to build an atomic bomb.
Source: Department of Defense