In January 1961, a B-52 Stratofortress carrying two thermonuclear Mark-39 nuclear weapons experienced a fuel leak, and began to break apart mid-air over Goldsboro, North Carolina. As the pilots lost control of the aircraft, one of the bombs accidentally ejected. Luckily, its attached parachute successfully deployed and allowed it to float slowly towards the ground before getting tangled in a tree. The other bomb remained onboard until impact, where it became submerged underneath almost 20 feet of mud.
Fortunately, the safety mechanism worked and neither bomb detonated, despite coming dangerously close. A forensic investigation found that three of the four safety switches on the first bomb had triggered inadvertently. The final switch had not, preventing the device from exploding. When excavators located the second bomb, the safety switch was off, and the device was set to “arm.” Had the fail-safes not worked correctly, a nuclear explosion equivalent to nearly 8 million tons of TNT might have devastated the eastern North Carolina town of Goldsboro and the surrounding vicinity.
News of the crash shocked the small farming community, especially as they learned of its deadly cargo. However, information about how close the bombs came to detonation remained classified until 2013, when a FOIA request by Command and Control author Eric Schlosser revealed additional details about the bomb’s safety mechanisms.
To reduce the risk of accidental or unauthorized nuclear detonation, newly elected President John F. Kennedy ordered a reduction of Strategic Air Command alert activity, and the installation of permissive action links (PALs), which required a secret code to activate a nuclear bomb.