Wikipedia: Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in the summer of 1946. Its purpose was to test the effect of nuclear weapons on naval ships. The series consisted of two detonations, each with a yield of 23 kilotons:[1] Able was detonated at an altitude of 520 feet (158 m) on 1 July 1946; Baker was detonated 90 feet (27 m) underwater on 25 July 1946. A third planned burst, Charlie, was cancelled.

The Crossroads tests were the fourth and fifth nuclear explosions conducted by the United States (following the Trinity test and the bombings of Hiroshima and Nagasaki). They were the first nuclear tests held in the Marshall Islands, and the first to be publicly announced beforehand and observed by an audience of invited witnesses and a large press corps.

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