Operation Crossroads: an atomic bomb is detonated underwater in the lagoon of Bikini atoll.

Nuclear testing: The Castle Bravo, a 15-megaton hydrogen bomb, is detonated on Bikini Atoll in the Pacific Ocean, resulting in the worst radioactive contamination ever caused by the United States.

In Operation Redwing (shot ''Cherokee''), the first United States airborne hydrogen bomb is dropped over Bikini Atoll in the Pacific Ocean;