A U.S. bomber on a practice run loses a hydrogen bomb

An entire hydrogen bomb went missing after a mid-air collision over the state of Georgia. It happened when a B-47 bomber on a training run with a (for some reason, live) hydrogen bomb crashed into an F-86 fighter. The much smaller fighter was completely destroyed, while the B-47 remained airborne, albeit greatly damaged. But they needed to lose some weight, fast.

On this day, February 5, 1958, the United States dropped a hydrogen bomb on itself. To avoid exploding during emergency landing procedures, and to reduce the weight and keep the stricken plane afloat, the B-47 was granted permission to drop its payload, undetonated, into the Atlantic, somewhere off the eastern coast of Georgia, near the little resort town of Tybee.

There were contradictory accounts as to whether the bomb was real or not: initially, reports said it was a dummy, and the nuclear core was taken out. Later reports confirmed the bomb was indeed real, core and all. While no radiation or any ill effects have been traced to the lost bomb, the U.S. Air Force has occasionally gone back to the island to look for it, so far without success.