A group of civilian researchers claims to have discovered the wreckage of USS Indianapolis, a cruiser that was torpedoed by a Japanese submarine in the morning of July 30, 1945, during World War Ii.

According to the US Navy, the wreckage was found on the floor of the North Pacific Ocean, about 5,500 meters below the surface. The Navy says it wants to keep the location restricted and confidential and claims ownership of the cruiser.

USS Indianapolis sank within 12 minutes after the assault

The USS Indianapolis was destroyed somewhere between Leyte and Guam in the Philippine Sea.

The ship sank within 12 minutes after the assault, and no distress call was ever received. Prior to the attack, the ship had completed a secret mission of delivering parts of the nuclear bomb nicknamed “Little Boy” to Tinian Island, an American base at that time. The ship also delivered enriched uranium fuel to be used in the bomb that was eventually dropped over Hiroshima a few days later.

Approximately 1,196 sailors were onboard USS Indianapolis when it was torpedoed by the Japanese submarine. Of these sailors, about 800 people survived the initial sinking of the ship, but only 316 of them could eventually survive the shark attacks, drowning, and dehydration in the ocean over next four to five days.

Of 316 survivors, 22 are still alive today. Ship's location at the time of attack became a mystery forever because of its quick sinking and lack of a distress call.

Research team was led by Microsoft co-founder Paul Allen

The civilian research team that found the wreckage was led by Microsoft co-founder Paul Allen, who described the discovery as "truly humbling".

The team found the vessel on 18 August, after another research suggested a specific region in the Pacific Ocean where USS Indianapolis was sighted the night before it was torpedoed.

When Allen’s research team discovered the wreckage, they knew it was Indianapolis because of its hull markings. The identification became comparatively simple with some fragments bearing the name of the warship.

A spokesman for the 22 survivors said they had "longed for the day when their ship would be found".

Mr. Allen's research vessel Petrel that helped find the warship can accommodate a crew of 16 and is fitted with special equipment for exploration work. Earlier, it had found the wreckage of an Italian naval vessel and a Japanese warship destroyed during World War Two.

In a statement, Sam Cox, director of the Naval History and Heritage Command, said there are lessons to be learned even in worst disasters, and these lessons need to be passed on so that the same mistakes are not repeated and so lives are saved.