Atom bomb over North Carolina came close to detonating in 1961 crash, documents say

One of two nuclear bombs that fell near Raleigh, N.C., during a military accident more than 50 years ago came frighteningly close to detonating, newly-released documents reveal.

It has long been known that a pair of 4-megaton hydrogen bombs fell from a stricken B-52 as it broke apart over Goldsboro, N.C., on Jan 24, 1961, at the height of the Cold War. But documents just released by the National Security Archive show that one bomb's arming mechanism switched from "safe" to "armed" on impact, while the other bomb fluttered under a parachute and would have exploded in the sky if two cockpit wires had happened to touch as the plane disintegrated.

"This bomb had the potential to make the one used in Hiroshima look like the work of a cap gun," said Eric Schlosser, who obtained the documents approximately a year before they were obtained by the National Security Archive at George Washington University.

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Schlosser, who wrote about the incident in his 2013 book, "Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety," said the bomb brought to Earth by parachute, dubbed "Weapon I," was actually the one that came closest to detonating, even though its arming mechanism remained on "safe." The explosive performed just as a nuclear weapon is designed to function in wartime, completing five of the six steps to detonation, and only a single low-voltage switch prevented the explosion.

"It behaved as though it was dropped over the Soviet Union at the time," Schlosser said.

Other experts agree.

"When the B-52 disintegrates in the air it is likely to release the bombs in a near normal fashion," wrote Parker Jones, who analyzed the incident at the time for the Sandia National Laboratories and wrote a report entitled "How I learned to mistrust the H-Bomb."

As it turned out, the bomb that fell to the ground at 700 miles per hour did the most damage, burrowing some 12 feet into the ground. Unlike the other bomb, it was never in danger of detonating despite the impact moving its arming mechanism to the "armed" position. Jack ReVelle, who was an Air Force weapons disposal specialist in charge of disarming the two 11 1/2 -feet bombs, remembered when his men reported seeing the switching device as they dug their way down into the crater formed on impact.

“Until my death I will never forget hearing my sergeant say, ‘Lieutenant, we found the arm/safe switch,’” ReVelle told students at East Carolina University in 2013. “And I said, ‘Great.’ He said, ‘Not great. It’s on arm.”

The fact that the arming mechanism on the second weapon moved on impact prompted the military to order new switches immediately.

“So even though weapon 2 was further from detonation, the fact that the switch used to arm the weapon could be altered by an impact, shows its safety shortcoming,” William Burr, an analyst from the National Security Archive said.

The B-52 had been on a routine 12-hour mission and suddenly lost 19 tons of fuel pressure within minutes, according to local reports. The pilot was able to straighten the plane at 10,000 feet and aimed it for nearby Seymour Johnson Air Force Base until its right wing broke off. One witness described the plane as streaking through the sky like a Roman candle.

The pilots survived, and no one was killed on the ground. But had either bomb detonated, history would have been made in the worst possible way.

"It would have created a crater eight football fields wide," ReVelle said. "It would have destroyed every structure within a four-mile radius. There would have been a 100-percent kill zone for eight and a half miles in every direction."