2. In 1950 a nuclear bomb crashed into a mountain in New Mexico
On April 11, 1950, just three minutes after take-off from Kirtland Air Force Base in Albuquerque, New Mexico, for reasons unknown a USAF B-29 bomber carrying a nuclear weapon crashed into a nearby mountain. The crash of the B-29 resulted in an enormous fire, described by The New York Times as being visible from 15 miles away, and caused the deaths of all thirteen crew members aboard.
However although the bomb’s casing was completely destroyed in the crash, causing the explosives contained to ignite and explode from contact with the plane’s burning gasoline, as per Department of Defense safety regulations the nuclear weapon’s core was stored separately from the bomb itself preventing nuclear detonation. After a comprehensive clean-up operation lasting several months and involving hundreds of personnel, all four spare detonators and all nuclear materials and components were safely recovered from the wreckage.