If you've seen Jaws, then you know the basics about the tragic descent of the USS Indianapolis. Considered one of the most grievous disasters in the history of the American Navy, it saw the sinking of a US heavy cruiser towards the end of WWII and the gruesome loss of a majority of its crew. If the Japanese strike had been carried out just a few days earlier, the crew might not have been able to deliver materials for the first working atomic bomb, Little Boy.