Near Nuclear disaster over North Carolina in 1961
I never heard this story. Nuclear bombs were dropped over North Carolina in 1961 when a B-52 bomber came apart in flight and released the bombs - and in the process one of the bombs began arming itself as it fell. One of the bombs was only 1 fail safe away from detonating. According to the story the bomb was @260x as powerful as the Hiroshima bomb.
US plane in 1961 'nuclear bomb near-miss'
" three out of the four fail safe mechanisms failed"
Here's the event detail from wikipedia
Apparently the uranium from one of the bombs was buried so deeply after the bomb impacted into the field that it is still there - at estimated 180 ft below the surface of the ground.
Here's some eye-witness reports from the local papers in Goldsboro, NC
"So despite the fact the the military claims to have recovered many
components of that Mark 39, those who live near the site say there is
still a bomb in the ground."
Here's apparently a picture of the land where the bomb is buried under
According to comments here (formerspook.blogspot.com) of the two bombs that fell, the parachute on only 1 opened (apparently the bombs are designed to float down on parachutes) and that bomb was the one that was only 1 fail safe from detonating. The one has parts still buried in the field apparently fell so fast that it was less of a risk and couldn't arm properly as they were designed to fall slowly by parachute and that process would arm them. There's good comments at that site.