A submarine finds Indianapolis in the dark, unescorted; the cruiser is gone in twelve minutes
Days earlier, USS Indianapolis had raced across the Pacific at 29 knots carrying enriched uranium for the atomic bomb, then delivered it to Tinian and sailed on toward Leyte without an escort. Just after 11 pm on July 29, 1945, Lt. Cdr. Mochitsura Hashimoto's submarine I-58 fired six torpedoes into the cruiser's starboard side, mistaking her for a battleship. Indianapolis rolled and sank in twelve minutes, taking roughly 300 men down with her. The remaining 890 spent four days in open water before rescue, and only 316 of the original 1,195 crew survived.
Indianapolis had just finished the mission that made the atomic bombing of Japan possible, hauling Little Boy's uranium core across the Pacific faster than any ship in the fleet. Her sinking, still the worst single loss of life in U.S. naval history, forced the Navy to confront how a cruiser carrying the most valuable secret cargo of the war had sailed without escort, and left Captain McVay court-martialed in a case the Navy did not formally clear until decades later.
QHow fast did Indianapolis actually travel on her uranium run to Tinian?
She averaged 29 knots for the entire crossing from San Francisco, an extraordinary sustained speed for a heavy cruiser in 1945 and a pace the Navy pushed deliberately, since the uranium discs locked in Captain McVay's own quarters were needed on Tinian as fast as steel and fuel could get them there. She left Hunters Point Naval Shipyard within hours of the Trinity test flash over New Mexico on July 16, and reached Tinian by July 26, a ten-day run that outpaced almost anything else moving across the Pacific that summer.
QWhat did the Japanese submarine crew think they had actually sunk?
Lt. Cdr. Hashimoto and his crew logged their kill as an Idaho-class battleship, not a cruiser. Indianapolis was a Portland-class heavy cruiser, considerably smaller than the battleship I-58's crew believed they had destroyed. The misidentification stood in Japanese records for the rest of the war, and Hashimoto himself never realized the actual size and identity of the ship he sank until much later.
QHow were the sailors finally recognized for what they endured?
More than seventy years after the sinking, the surviving crew of Indianapolis, along with those who died, were collectively awarded the Congressional Gold Medal on December 20, 2018, one of the highest civilian honors Congress can bestow. The recognition came a year after searchers had already located the wreck itself, closing out two long-delayed reckonings with the same ship in the space of twelve months.
