John Woolston didn’t know what was being loaded onto his ship, the USS Indianapolis, in San Francisco in 1945, but the Massachusetts Institute of Technology graduate had some suspicions.

“I read a lot and I was aware of things going on with uranium,” the 93-year-old Makiki resident said. “I knew, back of my mind, the existence of a probability of something like this happening.”

History soon confirmed that the heavy cruiser had transported to Tinian Island components of the “Little Boy” atom bomb that was air-dropped on Hiroshima on Aug. 6, 1945, helping end the war in the Pacific.

The crew of the Indianapolis would pay a terrible price for their top-secret, high-speed delivery across the Pacific when the cruiser was sunk by a Japanese submarine between Guam and the Philippines on July 30 of that year.

Of a crew of 1,196, nearly 900 went into the water. Just 316 to 317 survived injuries, delirium, dehydration and sharks over nearly five days, forgotten by the Navy as they clung to life and each other floating in the sea. It was one of the worst disasters in Navy history.

Patrick Finneran, former executive director of the USS Indianapolis Survivors Memorial Organization, wrote in 1994 that the USS Arizona and USS Indianapolis were the alpha and omega of the war for the U.S. Navy.

The Arizona was sunk pierside at the start of the war, and Indianapolis “fought the good fight throughout the war, played such a key role in ending the war in the Pacific, saving hundreds upon thousands of American and allied lives, only to be the final casualty,” Finneran said.

In August, the wreck was discovered in 18,000 feet of water in the Philippine Sea.

On Friday, the Battleship Missouri Memorial will show the documentary “USS Indianapolis: The Legacy” on the fantail of the “Mighty Mo” in the film’s first screening in Hawaii.

Its makers said it took 10 years of filming and 104 interviews to craft the story of the ship and its crew. Just 19 survivors remain alive. A meet-and-greet will be held from 6:30 to 7 p.m., the screening is from 7 to 8:45 p.m., and a Q&A will be held from 8:45 to 9 p.m.

Woolston, damage control watch and junior repair division officer on the Indianapolis, and filmmaker Sara Vladic will be special guests.

The record-setting run across the Pacific, without ship escort, “was something that’s not usually done,” Woolston said in an interview. “But it was in an area that wasn’t considered particularly dangerous. And the high speed was helpful. The next one — I see no reason in the world why we weren’t given an escort.” The Navy knew of Japanese submarine activity in the area at the time.

The Indianapolis delivered the bomb to Tinian Island on July 26. On the way from Guam to the Philippines just after midnight on July 30, 1945, two torpedoes from the submarine I-58 slammed into the Indianapolis. Woolston had just gone to get coffee and a sandwich after finishing his watch.

“Almost immediately there was a loud, hollow, metallic boom from forward,” he said in a biography. “The ship shook and great whirling caterpillars of orange flame flew aft into the wardroom.”

The ship went down in 12 minutes. Woolston wound up in the water in a large group with Dr. Lewis Haynes, the chief medical officer. Haynes in a later account said black fuel oil got into the men’s eyes and noses. Those with life jackets supported men without jackets, he said.

And there were the sharks.

“There were plenty of sharks. You could see them. The water was crystal clear,” said one crew member in the film.

Added another: “First day, I think we lost maybe 20 that first day. The second day was carnage all over.”

Delirium from being in the water, which brought chills and fever, and dehydration took a heavy toll. Woolston recalled men taking off their life jackets and trying to drown others.

“I never gave up hope, even expectation, of rescue, though it was depressing when aircraft flew over without seeing us and there were no signs of search when we became overdue in port,” he said in the biography. Port officials were not required to report the non-arrival of the ship.

On Aug. 2, 1945, a PBY float plane landed and rescued 56 men, Woolston included. The remainder, including the ship’s commander, Capt. Charles B. McVay III, were picked up by ships.

The Indianapolis was sunk on July 30, but the Navy didn’t release the news until Aug. 15. Japan had just surrendered, and that overshadowed the tragedy at sea.

“I think it is a tale of things that went terribly wrong and people lived through it,” Woolston said. “It was the resiliency of the individual on one hand and the terrible loss that was effected because (the Navy’s ship-reporting rules) were not set up — because that should have never happened.”

For tickets to see the documentary, go to ussmissouri.org/ussindy.