At 12:14 a.m. on July 30, 1945, the USS Indianapolis was torpedoed by a Japanese submarine in the Philippine Sea and sank in 12 minutes. Of 1,196 men on board, approximately 300 went down with the ship. The remainder, about 900 men, were left floating in shark-infested waters with no lifeboats and most with no food or water. The ship was never missed, and by the time the survivors were spotted by accident four days later only 316 men were still alive. “So why did so many sailors die?”

The world's first atomic bomb was delivered by the U.S.S Indianapolis, to the island of Tinian on 26 July It was to be used in the Hiroshima bombing. The Indianapolis was then directed to prepare for the invasion of Japan. Due to the secret nature of the cargo and the urgency of the mission no records were kept about the naval ship and she sailed off on a route nobody knew about.

At 14 minutes past midnight, on 30 July 1945, the U.S.S Indianapolis was hit by two torpedoes fired by a Japanese submarine. The first blew away the bow, the second struck near midship on the starboard side adjacent to a fuel tank and a powder magazine. The resulting explosion split the ship to the keel, knocking out all electric power. Within minutes she went down rapidly by the bow, rolling to starboard. It took just 12 minutes to sink.

Of the 1,196 sailors aboard, about 900 made it into the water in the twelve minutes before she sank. Few life rafts were released. Most survivors wore the standard kapok life jacket. Shark attacks began with sunrise of the first day and continued until the men were physically removed from the water, almost five days later.

The men all clung together in groups of 150. The tiger sharks started to swim around the survivors on the second day – but they did not bite anyone. On the third day the sharks started to attack: “The day wore on and the sharks were around, hundreds of them. You'd hear guys scream, especially late in the afternoon. Seemed like the sharks were the worst late in the afternoon than they were during the day. Then they fed at night too. Everything would be quiet and then you'd hear somebody scream and you knew a shark had got him.” Once the shark attacks started almost 6 sailors were eaten every hour.

On the fourth day, the survivors were accidentally discovered by LT. (jg) Wilbur C. Gwinn and a seaplane under the command of LT. R. Adrian Marks was sent to lend assistance and report. Arriving hours ahead of help the Marks' crew began dropping rubber rafts and supplies. They observed men being attacked by sharks. Disregarding orders not to land, Marks landed and began picking up lone swimmers who were at greatest risk of shark attack. Learning the men were the crew of the Indianapolis, he radioed the news, requesting immediate assistance. Marks waited for help, all the while pulling nearly dead men from the water. When the plane was full, survivors were tied to the wing with parachute cord. Marks and his crew rescued 56 men that day. The Cecil Doyle was the first vessel on the scene. Homing on Marks' PBY in total darkness, the Doyle halted to avoid killing or further injuring survivors, and began taking Marks' survivors aboard.

Of the 900 who made it into the water, only 317 remained alive. After almost five days of constant shark attacks, starvation, terrible thirst, suffering from exposure and their wounds, the men of the Indianapolis were at last rescued from the sea. The impact of this unexpected disaster sent shock waves of hushed disbelief throughout Navy circles in the South Pacific. A public announcement of the loss of the Indianapolis was delayed for almost two weeks until August 15, thus insuring that it would be overshadowed in the news on the day when the Japanese surrender was announced by President Truman.