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.
Japanese submarines in the Pacific War
The sank the heavy cruiser shortly after it delivered parts for the atomic bomb Little Boy to the island of Tinian. The loss of the "Indianapolis" was not noticed for four days, which resulted in the deaths of hundreds of American sailors at sea, and constituted the greatest loss of life at sea in a single incident in the history of the United States Navy (the sinking of the USS Arizona at Pearl Harbor resulted in greater deaths).