On January 24, 1961, two hydrogen bombs fell from a B-52 as it broke apart in the sky and hit the ground near the city of Goldsboro.

The Air Force bomber suffered a "failure of the right wing" and broke in half while flying over North Carolina, said documents revealed by the National Security Archive this week.

As the bombs were plunging toward the ground the parachute for one failed to deploy.

The weapon whose parachute opened landed intact but the second bomb landed in a "free fall" with the impact of the crash putting it in the "armed" setting.