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 in the county, while 86% commute in, with 27% commuting from Fairfax County. An additional 92,784 people commute out for work, with 42% commuting to DC, and 29% commuting to Fairfax County. A number of federal agencies are headquartered in Arlington, including the Air Force Office of Scientific Research, American Battle Monuments Commission, DARPA, Diplomatic Security Service, Drug Enforcement Administration, Foreign Service Institute, the DHS National Protection and Programs Directorate, Office of Naval Research, Transportation Security Administration, United States Department of Defense, United States Marshals Service, and the United States Trade and Development Agency. Companies headquartered in Arlington include AES,