Divers Find Sunken WWI Submarine, 100 Years After It Disappeared

One of Australia's oldest naval mysteries has been solved.

A century-old naval mystery has been solved in Australia, where divers discovered a submarine that mysteriously sunk during World War I.

The AE1 vanished off the island of New Britain in Papua New Guinea in 1914, with 35 crew members aboard from Australia, New Zealand and Britain.

For 103 years, no one knew what had happened to the vessel and its brave crew. In recent decades, search after search failed to find any trace of the submarine.

But on Thursday, Australian Defense Minister Marise Payne said the wreck of the historic submarine was located intact more than 984 feet below the surface in a search using a Dutch-owned survey vessel.

The cause of the submarine's sinking is unclear.

At the time of the discovery, the crew aboard the survey vessel conducted a service to honor those who died.

AE1 was the first Allied submarine loss of the war and the first in wartime for the Australian Navy.

The vessel was never believed to have been sunk by an enemy ship. Instead, experts believe it most likely struck a reef, causing it to depressurize.