The World War II cruiser USS Indianapolis (CA 35), which was lost July 30, 1945 is seen off the Mare Island Navy Yard, California, U.S. on July 10, 1945, after her final overhaul and repair of combat damage. Courtesy Bureau of Ships Collection in the U.S. National Archives. (U.S. Navy/Handout via REUTERS)

SAN FRANCISCO, Aug. 20 (Xinhua) -- A team of civilian researchers has found wreckage from the USS Indianapolis, the naval flagship of the U.S. Navy Fifth Fleet lost in the final days of the World War II, or WWII, 5,500 meters below the surface on the floor of Philippine Sea in the North Pacific Ocean.

The finding was posted by Microsoft Corporation co-founder and philanthropist Paul G. Allen on Saturday and confirmed by the U.S. Navy.

"We've located wreckage of USS Indianapolis in Philippine Sea at 5500m below the sea," Allen declared in a posting on his website, www.paulallen.com.

The discovery was made Friday by the 16-person expedition team of Allen's Research Vessel (R/V) Petrel.

The Indianapolis was torpedoed by a Japanese submarine in the early morning hours of July 30, 1945, when it had just completed a secret mission of delivering components of one of the two nuclear weapons that were dropped on Japan.

The 9,800-ton Portland Class heavy cruiser, commissioned in November 1932, sank in 12 minutes, making it impossible to deploy much of its life-saving equipment. Of the 1,196 sailors and Marines onboard, only 316 survived.

During WWII, the Indianapolis served with honor from Pearl Harbor, earning 10 battle stars.

"To be able to honor the brave men of the USS Indianapolis and their families through the discovery of a ship that played such a significant role during World War II is truly humbling," Allen said in his web posting.

While the expedition team on the R/V Petrel will continue the process of surveying the full site, the U.S. Navy said the work is compliant with U.S. law, "respecting the sunken ship as a war grave and not disturbing the site."