History of Hawaii
Pearl Harbor was surprisingly attacked on December 7, 1941 by the Imperial Japanese Navy, killing 2,403 people and sinking the main American battleship fleet. Fortuitously, the four Pacific aircraft carriers were not in port and escaped damage. Hawaii was put under martial law until 1945. Unlike the West Coast of the United States in which 100,000 ethnic Japanese citizens were interned, the Japanese American population in Hawaii completely avoided such similar fate, though hundreds of pro-Japan leaders were arrested. Pearl Harbor was the U.S.' main forward base for the Pacific War. The Japanese tried to invade in summer 1942 but were defeated at the Battle of Midway. Hundreds of thousands of American soldiers, sailors, Marines, and airmen passed through on their way to the fighting.
Prisoner of war
Allied POW camps and ship-transports were sometimes accidental targets of Allied attacks. The number of deaths which occurred when Japanese "hell ships"—unmarked transport ships in which POWs were transported in harsh conditions—were attacked by US Navy submarines was particularly high. Gavan Daws has calculated that "of all POWs who died in the Pacific War, one in three was killed on the water by friendly fire". Daves states that 10,800 of the 50,000 POWs shipped by the Japanese were killed at sea while Donald L. Miller states that "approximately 21,000 Allied POWs died at sea, about 19,000 of them killed by friendly fire."