The USS Indianapolis, a heavy cruiser of the United States Navy, was assigned a secret mission during World War II: delivering parts of the atomic bomb that would later be used on Hiroshima to the island of Tinian in the Pacific. The ship completed its task successfully but was soon torpedoed by a Japanese submarine and sank in just twelve minutes. Of the 1,196 men on board, only 316 survived, making this event the largest documented shark attack in maritime history. The ship’s cargo, which included parts of the uranium-based atomic bomb, was known only to two men: James Nolan and Robert Furman, both linked to the Manhattan Project, a top-secret research initiative that developed the first atomic weapons. The rest of the crew believed they were transporting standard military supplies. Under the command of Captain Charles McVay III, the USS Indianapolis traveled nearly 5,000 miles in less than ten days, a record pace for that time. After delivering its cargo, the USS Indianapolis continued toward Guam and the Philippines without a special escort. During the night, the Japanese submarine I-58 spotted the cruiser and launched torpedoes, causing the ship to sink in twelve minutes. Around 300 men died during the sinking, while the remaining 900 survivors were left adrift in the ocean without life jackets or immediate rescue. The survivors endured four days and four nights of extreme hardship, including dehydration, exhaustion, and attacks by white-tipped oceanic sharks. Rescue efforts were delayed, as the sinking was only discovered by chance when a patrol plane spotted an oil slick and floating figures nearly four days after the attack. This delay led to the deaths of more than 500 sailors, who succumbed to dehydration, exhaustion, or shark attacks. Captain McVay was partially held responsible for the sinking during a controversial trial, though the high command’s navigation orders were also cited as contributing factors. The tragedy highlights how a successful military mission can hide one of the darkest human tragedies of the twentieth century. The question of how many lives could have been saved if rescue efforts had been alerted earlier remains a subject of debate.