Two N-bombs nearly wiped out North Carolina in 1961: report

In 1961, the US escaped a disaster worse than the devastation wrought in the Japanese cities of Hiroshima and Nagasaki when a B-52 air force bomber broke in half mid-air and two nuclear bombs hit the ground in North Carolina, declassified documents show.
On January 24, 1961, a US bomber broke in half while flying over North Carolina. From the belly of the B-52 fell two bombs -- two nuclear bombs that hit the ground near the city of Goldsboro.
But thanks to a series of fortunate missteps, the US averted a major disaster.
Declassified documents that the National Security Archive released this week offered new details about the incident, the CNN reported.

The blaring headline read: "Multi-Megaton Bomb Was Virtually 'Armed' When It Crashed to Earth." Or, as Secretary of Defence Robert McNamara put it in back then, "By the slightest margin of chance, literally the failure of two wires to cross, a nuclear explosion was averted."
The MK39 bombs weighed 10,000 pounds and their explosive yield was 3.8 megatons compared to the bombs US dropped in Hiroshima and Nagasaki which were 0.01 and 0.02 megatons respectively. Some 90,000-166,000 people in Hiroshima and 60,000-80,000 people in Nagasaki were reportedly killed in the two bombings in August 1945.

The B-52 was flying over North Carolina when it suffered a "failure of the right wing," the report said.

As the plane broke apart, the two bombs plummeted toward the ground. The parachute opened on one; it did not on the other.
"The impact of the aircraft breakup initiated the fuzing sequence for both bombs," the summary of the documents said.
In other words, both weapons came alarmingly close to detonating.
Weapon 1, the bomb whose parachute opened, landed intact. Fortunately, the safing pins that provided power from a generator to the weapon had been yanked -- preventing it from going off.
Weapon 2, the second bomb with the unopened parachute, landed in a free fall. The impact of the crash put it in the "armed" setting. Fortunately -- once again -- it damaged another part of the bomb needed to initiate an explosion.

Eight crew members were aboard the plane that night. Five survived the crash, the report said.