'We nearly had a hydrogen bomb detonate a few days after JFK's inauguration' "A four-megaton nuclear bomb was one switch away from exploding over the US in 1961, a newly declassified US document confirms. Two bombs were on board a B-52 plane that went into an uncontrolled spin over North Carolina - both bombs fell and one began the detonation process. The document was first published in the UK's Guardian newspaper. The US government has acknowledged the accident before, but never made public how close the bomb came to detonating." A very close call indeed.