Hydrogen bombs dropped as doomed B-52 plunged to earth. One almost detonated.

A doomed Air Force B-52 accidentally dropped two hydrogen bombs on North Carolina in January 1961, and one came perilously close to exploding and scattering deadly radioactive fallout over the Eastern Seaboard, according to a recently declassified report.

The 4-megaton Mark 39 bombs -- each packing 260 times the explosive power of the weapon that decimated Hiroshima -- broke loose over Goldsboro, N.C., as the bomber went into a tailspin and crashed.

The Mark 39 hydrogen bomb had an explosive yield of 4 megatons, equal to 4 million tons of TNT. Two fell accidentally on Goldsboro, N.C., in 1961, and one nearly detonated.(Photo: U.S. Air Force)

All four safety mechanisms designed to prevent accidental detonation worked properly on one bomb, which landed in a meadow, but three failed on the other, and only a low-voltage switch kept it from exploding upon impact in a field in Faro, N.C., said the 1969 report.

The accident happened just three days after President John F Kennedy was inaugurated. Only one crew member survived the crash.

The report was obtained by Fast Food Nation author Eric Schlosser for his newest book, Command and Control, about the nuclear arms race. Schlosser found that between 1950 and 1968 alone, at least 700 "significant" accidents and incidents involving 1,250 nuclear weapons were recorded.

Mother Jonesfirst reported Schlosser's findings Sunday, and the Goldsboro incident attracted new attention Friday based on an article in the Guardian. The British paper also published the report, written by Parker F Jones, the supervisor of the nuclear weapons safety department at Sandia National Laboratories.

Source: Usatoday