United Airlines Flight 93 was United Airlines' scheduled morning transcontinental flight across the United States from Newark International Airport in Newark, New Jersey, to San Francisco International Airport in California. On Tuesday, September 11, 2001, the Boeing 757–222 aircraft operating the route was hijacked by four al-Qaeda terrorists as part of the September 11 attacks. It subsequently crashed into a field in Stonycreek Township, Pennsylvania near Shanksville during an attempt by some of the passengers to regain control.