World War II: Japanese submarine I-58 sinks the USS Indianapolis, killing 883 seamen. Most die during the following four days, until an aircraft notices the survivors.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

I-58 was a Japanese B3 type cruiser submarine that served in the final year of World War II. Her only significant wartime success came with a conventional torpedo attack upon USS Indianapolis on 30 July 1945. She was modified to carry Kaiten manned torpedoes, making several attacks that inflicted minor damage in exchange for every Kaiten launched being sunk. The submarine surrendered in September 1945, and was later scuttled by the United States Navy.

USS Indianapolis (CL/CA-35) was a Portland-class heavy cruiser of the United States Navy, named for the city of Indianapolis, Indiana. Launched in 1931, she was the flagship of the commander of Scouting Force 1 for eight years, then flagship for Admiral Raymond Spruance from 1943 to 1945 while he commanded the Fifth Fleet in battles across the Central Pacific during World War II.