January 1961. The Cold War is on fire, effulgent, clandestine, and deadly. The nuclear Triad, the three ways we intended to deliver atomic weaponry consisted of the hardened land silos, submarines, and of course the Strategic Air Command, nuclear weapons in the bomb bays of bombers that stayed in the air around the clock for over four decades. The saturation of nuclear stockpiles was a can of gas and the eventual nuclear accident was a match that could ignite by any misstep. That said, there have been a handful of random accidents that miraculously did not result in detonation.
One of them recently came to light with some routine declassification. On January 24th, 1961, a B-52, loaded with two Mark 39 thermonuclear bombs fell apart mid air. The right wing simply collapsed, and the plane disintegrated on the way down. The parachute actually opened on one of the bombs and not on the other. The two bombs both hit the ground, the detonation sequence in one of them had begun. The only reason a nuclear explosion did not vaporized Goldsboro North Carolina is that two wires that should have been connected on one of the bombs were broken in the impact. The other bomb did not go off because the “safing” mechanism that power the fuzing sequence also shattered on the impact.
Both MK39 bombs weighed 10,000 pounds and their explosive yield was 3.8 megatons, equivalent to the yield of the Fat Man and Little Boy (Hiroshima and Nagasaki): They were 0.01 and 0.02 megatons.
Sources: nuclearsecrecy.com, CNN