Bravo

Bravo test
Operation Castle
1954
Nam Island, Bikini Atoll
Surface burst
15Mt yield

The Bravo test created the worst radiological disaster in US history. Due to failures in forecasting and analyzing weather patterns, failure to postpone the test following unfavorable changes in the weather, and combined with the unexpectedly high yield, the Marshallese Islanders on Rongelap, Ailinginae, and Utirik atolls were blanketed with the fallout plume along with U.S. servicemen stationed on Rongerik.

The Japanese fishing vessel Daigo Fukuryu Maru (Fifth Lucky Dragon) was also heavily contaminated, with the 23 crewmen receiving exposures of 300 Rads, one of whom later died.

This incident created an international uproar, and a diplomatic crisis with Japan.