The unescorted Indianapolis carried almost 1,200 sailors and had just delivered to Tinian Island components of the atomic bomb that was dropped on Hiroshima, Japan. Its secret mission over, the cruiser departed Guam and steamed for Leyte, an island in the Philippines, for training.
But torpedoes from a Japanese submarine sent the ship, and up to 300 of its men, to the bottom of the ocean in just 12 minutes in the first hour of July 30, 1945. The frantic crew was unable to get off a successful distress signal.
Of an estimated 800 sailors who went into the water, only 316 survived the nearly five-day ordeal -- the rest succumbing to burns, dehydration, exhaustion, shark attacks and drowning.
While some Americans are familiar with the demise of the Indianapolis -- the highest loss of Navy personnel at sea -- a recent nugget of information sheds new light on where the ship was attacked.
Here are six questions about the USS Indianapolis and lessons learned:
What's the new clue on where the ship went down?
Richard Hulver, a historian for the Naval History and Heritage Command, knew that an LST -- an acronym for a cargo and troop carrier -- came across the USS Indianapolis 11 to 12 hours before the sinking.
Wanting to know more about the location of the encounter, Hulver did a Google search on "USS Indianapolis" and "LST."
In May 2015, the son of a U.S. sailor who was on the LST wrote a blog post
on the website of a fudge shop his family operates in Mackinaw City, Michigan. While the post did not give the number of the LST, Hulver found through records that Seaman 1st Class Francis G. Murdick was catching a ride on LST-779.
Hulver perused Murdick's personnel records and the LST's deck logs
, gleaning new information that shows the Indianapolis was likely farther west than the Navy had thought to be at the time of the attack. "This brings us closer to discovering the final resting place of the ship and many of her crew," Hulver said in a Navy statement about the discovery
There have been attempts over the years to find the Indianapolis, and another reportedly is planned for 2017
, likely to readjust the search zone because of the finding. Navy officials said there are no current plans for the military to launch a new one. The vessel is believed to be in water more than 3 miles deep and possibly on a side of a steep undersea mountain range, providing a small target for sonar.
What do survivors remember about the horror?
Vic Buckett recalled seeing the Indianapolis "standing straight up" before it slipped below the waves during the first hour of July 30, 1945. He was among former Indianapolis crew members who spoke with National Geographic
Many of those who spilled into the water were injured from the torpedo explosions. Survivors thought surely help must be on the way.
Compounding the disaster was the fact that port officials at Leyte were not required to report the arrival -- and ostensibly nonarrival -- of a ship. The Navy did not know of the sinking for a few days, when an anti-sub patrol airplane spotted an oil spill and survivors bobbing in the water.
Edgar Harrell recalled the desperate scene to National Geographic.
"At any given time you could look out and see big fins swimming around and around around. All of a sudden you heard a blood-curdling scream and you look and you see the shark had taken him under.
Day after day went by. Skin began rotting, and Dick Thelen recalled seeing "a lot of guys just crack, or drink the water, or give up, or swim off to an imaginary island."
Hulver said most of the crew were able to get life jackets, but many of the vests became waterlogged or would tend to slide down the body, increasing fatigue. Some sailors grabbed on to floating nets, or the extremely fortunate got into a life raft.
"It was survival mode. Pulling away from the group almost meant certain death. Those who pulled away were picked off by the sharks, or drank saltwater and they floated off."
What's the connection to 'Jaws'?
Robert Shaw, portraying Quint in "Jaws," gave a chilling monologue
when Richard Dreyfuss' Hooper asked him about the Indianapolis. Quint said he and the other men who survived the sinking bunched up in the water to ward off marauding sharks.
"And the idea was, the shark goes to the nearest man and then he'd start poundin' and hollerin' and screamin' and sometimes the shark would go away," Quint said. Sometimes he wouldn't go away."
Hulver said Quint's story is largely accurate but may exaggerate the number of those killed by sharks. No one knows for sure. In some instances, the predators targeted the bodies of those who had died from the elements.
"There certainly are sharks," the historian said. "You read more of dehydration, overexposure and the mental collapse. That is the tough part of the story to read."
"Jaws" isn't the only film to cover the story of the USS Indianapolis. There's been talk of a Robert Downey Jr. project. And "USS Indianapolis: Men of Courage" is scheduled to reach the big screen this fall. Nicolas Cage will portray Capt. Charles McVay III.
The production company touts its treatment as "the remarkable true story of survival. Filled with tense action and brave heroes, it is the ultimate untold story of WWII."
How were the sailors rescued?
For days, it seemed as if almost everything worked against the sailors and Marines as they bobbed over a 25-square-mile area in the Pacific. Survivors fired what emergency flares they had. "The flares did not have parachutes, and they did not stay in the air long enough for planes to see them," Hulver said.
The survivors were not spotted until August 2, 1945
. By then, only a few hundred were still alive.
A Navy plane on anti-submarine patrol spotted an oil slick and people in the water. A PBY Catalina amphibious plane circled the scene.
"He made the call he needed to land in the water. He was taxiing around and picking up survivors," Hulver said.
Lt. Adrian Marks, who piloted the Catalina, spoke to a reunion group 30 years later and detailed how his crew had to make "heartbreaking decisions."
''I decided that the men in groups stood the best chance of survival,'' Marks said, according to a New York Times
1998 obituary. ''They could look after one another, could splash and scare away the sharks and could lend one another moral support and encouragement.'' They concentrated on individuals. Somehow, the plane hauled 56 sailors away.
Ships were rushed to the scene to save the remaining sailors and Marines.
Capt. Edward Parke, commander of a Marine detachment on board, gave up his life vest on numerous occasions to others and worked to keep his men together and focused on surviving. He died on the second day in the water of exhaustion.
A medical officer constantly reminded others not to drink saltwater. "There is no coming back, they would die in a few hours," Hulver said.
What happened to the ship's commander?
was rescued about noon August 3, 1945 -- nearly five days after the Indianapolis sank.
A court-martial effectively ended his distinguished career. McVay was acquitted of one charge but was found guilty of endangering the crew by failing to have the Indianapolis zigzag. (The Japanese sub commander testified such a defensive maneuver would not have saved the ship.)
Hulver said he was impressed with McVay's leadership and the fact he did not try to shift blame. "He thought possibly he should have gone down with his ship."
Taking responsibility is a key component of Navy leadership, said Paul Taylor, a spokesman for the Naval History and Heritage Command. "It sometimes can be unforgiving and Capt. McVay knew that."
Many survivors believed the skipper had been made a scapegoat. A joint congressional resolution said his conviction was a "miscarriage of justice." It cited a denied request for an escort ship.
While the conviction has remained on McVay's record, President Bill Clinton in 2000 signed legislation that exonerated the captain "in light of the act that certain exculpatory information was not available to the court-martial board."
McVay did not live to see the exoneration. He took his life in November 1968.
What lessons are to be learned from the tragedy?
Hulver likens the cruiser's World War II service to a bookend: The cruiser was away from Pearl Harbor on training exercises on December 7, 1941, when Japanese planes pulverized the fleet. Over the next few years, it earned 10 battle stars and contributed right up to the end of the war by delivering the atomic bomb parts.
"They had no idea what they were carrying," the historian told CNN. "They were told the faster they deliver it, the shorter the war would be."
Days later, while heading for the Philippines, in what was considered the "backwaters of the war," the Indianapolis' story ended.
The loss of the USS Indianapolis brought major changes to reporting procedures for arrivals and nonarrivals of ships. During World War II, those were not required.
Now there are reporting requirements. The Indianapolis was sailing alone; since then any vessel with 500 or more on board has an escort, possibly a destroyer.
Lifesaving equipment, vests and boats also were improved.
Taylor, the Navy spokesman, said sailors today can be inspired by the struggle for survival and lessons learned. "It is important for them to remember the sacrifices they may need to make."