14. Two nuclear bombs fell on North Carolina in 1961, and one remains buried under a farm to this day
On January 24, 1961, a USAF B-52 bomber on airborne alert – part of the US nuclear deterrence strategy during the Cold War – suddenly caught fire due to a critical leak in a wing fuel cell. Causing structural failure in the aircraft, the bomber exploded and broke apart in mid-air 12 miles north of Seymour Johnson Air Force Base, North Carolina. Of the eight crewman aboard the B-52, five successfully ejected and parachuted to safety whilst two died in the effort and a further one succumbed to injuries upon landing. The resulting breakup of the aircraft released the bomber’s two Mark-39 hydrogen bombs from a height of between 2,000-10,000 feet, which subsequently plummeted towards the ground.
The first bomb activated and begun the steps necessary to arm itself for nuclear detonation, initiating three of the four arming devices including the charging of the firing capacitors. Crucially the 100 foot diameter custom-designed parachute activated successfully during free fall, allowing the nearly fully armed bomb to land safely with minimal damage and preventing detonation. The second bomb’s parachute however did not, and the device instead plunged into a muddy field at approximately 700 mph and disintegrated. Security analyst Daniel Ellsberg later determined the weapon could have accidentally fired because “five of the six safety devices had failed”, and nuclear physicist Ralph Lapp calculated “only a single switch” had “prevented the bomb from detonating and spreading fire and destruction over a wide area.”
The tail of the second bomb was later discovered almost 20 feet below the surface, and after evacuation of the nearby farmland and an extensive excavation some of the bomb’s radioactive materials including the plutonium and tritium bottle were recovered. However most of the thermonuclear stage of the bomb, including the enriched uranium core estimated to lie around 55 feet below ground, was never recovered. In order to prevent discovery or accidental disturbing, the Air Force fenced off the area and purchased an easement requiring permission to be obtained before any digging could occur on the land. The incident was sufficiently severe that President Kennedy was provided a full briefing on over 60 nuclear accidents that had occurred since the Second World War, and the U.S. and Soviet Union placed new safety devices on their nuclear arsenals.