On January 24, 1961, a USAF B-52 Stratofortress carrying two Mark 39 thermonuclear bombs suffered a severe fuel leak in its right wing during a routine patrol over Goldsboro, North Carolina. The aircraft broke apart mid-air at 10,000 feet, casting its crew and deadly payload into a tailspin. As the bomber disintegrated, the two 4-megaton hydrogen bombs detached from the wreckage.
Each bomb possessed explosive power roughly 250 times greater than the weapon dropped on Hiroshima. One bomb drifted down smoothly via parachute and landed intact in a tree. The second bomb plummeted unchecked into a muddy field at nearly 700 miles per hour, breaking into pieces upon impact.
When military response teams recovered the parachuted bomb, they made a chilling discovery: the crash had triggered every single step of the arming sequence. The bomb's lanyard had pulled, the arming wires had detached, the batteries had charged, and the firing mechanism had been activated. Out of six independent safety mechanisms designed to prevent an accidental detonation, five had failed under the stress of the crash.
The final, low-voltage toggle switch—a simple electrical component—was the only thing that prevented a catastrophic nuclear blast that would have altered the geography and political history of the United States. Declassified documents later revealed how perilously close the nation came to nuclear disaster on domestic soil.