Her sinking led to the greatest single loss of life at sea in the history of the U.S. Navy. On 30 July 1945, after a high-speed trip to deliver parts for Little Boy, the first atomic bomb used in combat, to the United States air base at Tinian, the ship was torpedoed by the Imperial Japanese Navy submarine I-58 while on her way to the Philippines, sinking in 12 minutes. Of 1,196 crewmen aboard, approximately 300 went down with the ship. The remaining 900 faced exposure, dehydration, saltwater poisoning, and shark attacks while floating with few lifeboats and almost no food or water. The Navy learned of the sinking when survivors were spotted four days later by the crew of a PBY Catalina on routine patrol. Only 317 survived.