Here's one from the Infamous Moments in Nuclear History files:
At 6:45 AM (local time) on March 1, 1954 at Bikini Atoll in the Marshall Islands the United States detonated its first dry fuel thermonuclear hydrogen bomb device in the test code named Castle Bravo. It was the most powerful nuclear device ever detonated by the U.S. with an explosive yield of 15 megatons (scientists expected a yield of 4 to 6 megatons), roughly 1,200 times more powerful than the atomic bombs dropped on Hiroshima and Nagasaki.
Castle Bravo was supposed to be a secret test, but because its designers underestimated its yield, things went dreadfully wrong in a flash. Because of the fission products, huge yield and shifting winds, radioactive fallout from the cloud spread quickly and far, contaminating over seven thousand square miles of surrounding ocean and nearby inhabited islands including Rongerik and Rongelap. The flash could be clearly seen 250 miles away (some secret!).
The nearby islands' inhabitants as well as U.S. soldiers stationed there for the test were exposed to the radioactive fallout, and subsequently evacuated. All were exposed to significant levels of radiation; although short term effects were mild, long term effects were significant for many.
Crewmembers of the Japanese tuna fishing boat, the Daigo Fukuryū Maru, or Lucky Dragon 5 were fishing outside of the declared exclusion zone when Castle Bravo detonated. The ship was covered in fine ash soon after the explosion. By the time the ship returned to Japan all 23 crew members were suffering from the effects of acute radiation syndrome - including nausea, headache, burns, pains in the eyes, and bleeding from the gums - and were admitted to hospitals.
One of the crew, chief radio operator Aikichi Kuboyama, died on September 23 from the effects of radiation exposure. His last words were:
I pray that I am the last victim of an atomic or hydrogen bomb.
The Daigo Fukuryū Maru was one of several hundred fishing boats and their crews exposed to the fallout from Castle Bravo. The Daigo Fukuryū Maru incident helped bring about a strong anti-nuclear movement in Japan.
The U.S. continued its atmospheric nuclear testing, conducting 67 tests at Bikini and Enewetak atolls between 1946 and 1958 leaving a legacy of contamination and death. "840 Marshall islanders are believed to have died of health problems caused by the tests. As of the end of 2003, more than 1,000 islanders were suffering from symptoms believed related to radiation exposure." Today (54 years later) the Marshall Islands are still contaminated, and radioactive cesium is found in water and fruits.
Today's anti-nuclear movement is a global movement that must continue to grow at a time when we need to bring strong pressure to bear on our governments to disarm. Let us hope that it will not take an incident like the one involving the Daigo Fukuryū Maru to make people rise up against the nuclear monster that continues to threaten humankind.
Let us pray (and work so) that there will be no more victims.
LeonardReference: Japan Times editorial: Nuclear Tragedy in the Pacific, Sunday March 1, 2009