On this date in 1946, the United States detonated Shot Able, the first of what was to be three tests in Operation Crossroads. It was also the first publicly-announced nuclear test, which was located at Bikini Atoll. It yielded 21 kilotons, was dropped from a B-29 bomber, and detonated at an altitude of 520 feet.
Ultimately, only two tests were conducted. Shot Charlie was called off due to higher radioactive contamination than previously predicted.