On November 11, 1972, three men armed with guns and hand grenades hijacked Southern Airways Flight 49. The hijackers threatened to crash the plane into a nuclear reactor in Oak Ridge, Tennessee, unless they were paid $10 million. Facing a potential nuclear disaster, Southern delivered part of this money to the hijackers, who refused to release the passengers and continued to Cuba, where they were arrested. Realizing the potential mass lethality of such hijackings, the Federal Aviation Administration began full passenger and carry-on luggage screening at American airports shortly thereafter, starting on January 5, 1973.