Operation Castle
A series of nuclear weapon tests that the USA conducted in 1954. Most noteable about these is that this series included the accidental largest nuclear weapon ever tested by the USA in the test codenamed Bravo. This device released energy equivalent to 15 Millions of tons of TNT. The predicted yield was 6 megatons. It blasted a crater with about 2 km diameter in the Bikini Atoll where it was tested.When the wind turned unexpectedly, this explosion turned into the worst radiological disaster in the USA ever seen. Several people were irradiated by the nuclear fallout, among them inhabitants of the nearby Marshall Islands and some Japanese fishers, one of whom died later. An area of about 1% of the Earth Surface had to be regarded as a security zone.