Billionaire Microsoft mogul Paul Allen announced on Saturday (NZT) that a research vessel belonging to his organisation has found wreckage from the USS Indianapolis in the Philippine Sea.
Seventy-two years after the event, wreckage of the US warship which delivered Hiroshima A-bomb components and was sunk by a Japanese torpedo off the Philippines in the final days of WWII has been found.
The ship is more than 5.5km below the surface of the Pacific Ocean, the Navy said on Saturday.
The cruiser was returning from its mission to deliver components for the atomic bomb that would soon be dropped on Hiroshima when it was fired upon in the North Pacific Ocean by a Japanese submarine on July 30, 1945.
It sunk in 12 minutes, according to the Naval History and Heritage Command in Washington.
No distress signal was sent. About 800 of the 1197 crew members aboard survived the sinking, but just 316 were rescued alive five days later, with the rest lost to exposure, dehydration, drowning and sharks.
After a Navy historian unearthed new information last year about the warship's last movements that pointed to a new search area, a team of civilian researchers led by Mr Allen, a Microsoft Corp co-founder, spent months searching in a 1500 square kilometre patch of ocean.
With a vessel rigged with equipment that can reach some of the deepest ocean floors, members of Mr Allen's team found the wreckage on Saturday, he said in a statement on his website. The Navy asked Mr Allen to keep the precise location confidential.
He said the discovery was a humbling experience and a means of honouring sailors he saw as playing a vital role in ending WWII.
"While our search for the rest of the wreckage will continue, I hope everyone connected to this historic ship will feel some measure of closure at this discovery so long in coming," he said.
The Navy said it plans to honour the 22 survivors from the Indianapolis still alive, along with the families of the ship's crew.