On July 30, 1945, a Japanese Imperial Navy submarine torpedoed and sank the U.S.S. Indianapolis in the Pacific. Because of its secret mission, to deliver key parts of the atomic bomb that later was detonated over Hiroshima, the sinking of the ship went unreported. By the fourth day adrift in the ocean, 600 of the 900 men who survived the initial explosion had succumbed to death due to dehydration and shark attacks. Harpo Celaya, one of the survivors, recalls the moment when a rescue plane was finally spotted.