September 11, 2012
Pentagon - September 11

September 11, 1941 - ground was broken for the Pentagon Building in Arlington - construction began two months later. Sixteen months later, the Pentagon was complete.

September 11, 2011 - Sixty years to the day after the groundbreaking, a passenger jet piloted by terrorist hijackers crashed into the Pentagon, killing all aboard the jet and more than a hundred people inside the building itself. The jet crashed into a wing that was being remodeled, so many of the offices were unoccupied; otherwise, the death toll would have been much higher.