Two nuclear bombs plummeted from a splintering B-52 bomber in January 1961 and plopped down outside Goldsboro, North Carolina, according to newly-declassified government documents. And though the plane's disintegration triggered the "fuzing sequence" in both weapons, neither went off because of miraculous technical issues.
One bomb was missing pins necessary for detonation, but only because they were ripped out in the crash. The other — whose parachute failed to deploy — slammed into the ground, initiating the explosion sequence but simultaneously damaging another part necessary for detonation.
"By the slightest margin of chance," former Defense Secretary Robert McNamara put it, "literally the failure of two wires to cross, a nuclear explosion was averted."