History of the United States (1991–2008) South Tower less than twenty minutes later at 9:03 A.M. (EST), resulting in the collapse of both 110 story skyscrapers, and the destruction of the World Trade Center. The third hijacked plane, American Airlines Flight 77, was crashed into the Pentagon (the headquarters of the United States Department of Defense) in Arlington County, Virginia, demolishing a section of the outer southwest facing wall. After discovering that their plane, United Airlines Flight 93, was going to be used as a missile, passengers attempted to regain control of the plane which had been redirected towards Washington, D.C. However, after regaining control from
Arlington County, Virginia the vast majority originating from Washington Metro stations. Arlington is served by the Orange, Blue, Yellow, and Silver lines of the Washington Metro. The Metro stations in Arlington are the only stations outside of Washington, D.C. where the system's original Brutalist architecture can be found. Additionally, Arlington is served by Virginia Railway Express commuter rail, Metrobus (regional public bus), Fairfax Connector (regional public bus), Potomac and Rappahannock Transportation Commission (PRTC) (regional public bus), (DASH bus) (regional public bus) and a county public bus system, Arlington Transit (ART). Metroway, the first bus rapid transit (BRT) in the D.C. area, is a