Thomas Edward Burnett Jr. was an American who was the vice-president and chief operating officer of Thoratec Corporation, a medical devices company based in Pleasanton, California; he resided in nearby San Ramon, California. On September 11, 2001, Burnett was a passenger on board United Airlines Flight 93, which was hijacked as part of the September 11 attacks. He, along with other passengers, formed the plan to retake the plane from the hijackers, and led the effort that resulted in the crash of the plane into a field in Stonycreek Township near Shanksville, Pennsylvania, thwarting the plan of the hijackers to crash the plane into a building in Washington, D.C., most likely either the U.S. Capitol Building or the White House.

United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four al-Qaeda terrorists on the morning of September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a federal government building in the national capital of Washington, D.C. The mission became a partial failure when the passengers fought back, forcing the terrorists to crash the plane in Somerset County, Pennsylvania, preventing them from reaching al-Qaeda's intended target, but killing everyone aboard the flight. The airliner involved, a Boeing 757-222 with 44 passengers and crew, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California, making it the only plane hijacked that day not to be a Los Angeles–bound flight.