The USS Indianapolis
The USS Indianapolis was hit by two types of 95 torpedoes launched by a Japanese submarine. It sank after this. There were 1,196 people aboard the ship, 300 of whom went down with it. The Navy did not know about it right away, which was why the survivors had been in the water for three and a half days. When the rescuers got there, only 317 survived. Many of them died from thirst, salt poisoning, and exposure. However, the most unfortunate ones died after encountering tiger sharks and oceanic whitetip sharks. What a way to go.

The USS Indianapolis