The United States faced a near disaster when two hydrogen bombs were accidentally dropped over Goldsboro, N.C. in early 1961 and one of the devices began to detonate.
A secret document with details about the incident was obtained by investigative journalist Eric Schlosser under the Freedom of Information Act, according to The Guardian.
The bombs reportedly fell to the ground after a B-52 bomber broke up in mid-air, and one of the devices acted as a nuclear weapon was designed to behave in warfare – its parachute opened, its trigger mechanisms engaged, and only one low-voltage switch prevented a massive disaster.
According to the newly-published document, a senior engineer in the Sandia national laboratories responsible for the mechanical safety of nuclear weapons concludes that "one simple, dynamo-technology, low voltage switch stood between the United States and a major catastrophe."
Writing eight years after the accident, Parker F. Jones found that the bombs that dropped over North Carolina in January 1961, were inadequate in their safety controls and that the final switch that prevented disaster could easily have been shorted by an electrical jolt, leading to a nuclear burst. "It would have been bad news – in spades," Jones wrote.
One of the bombs fell into a field near Faro, N.C. Jones found that of the four safety mechanisms designed to prevent unintended detonation, three failed to operate properly in that bomb. When it hit the ground, a firing signal was sent to the nuclear core of the device, and it was only that final, highly vulnerable switch that averted calamity. "The MK 39 Mod 2 bomb did not possess adequate safety for the airborne alert role in the B-52," Jones noted.
The Telegraph reports that fallout could have spread over Washington, Baltimore, Philadelphia and even New York City, threatening the lives of millions of people.