A longstanding mystery surrounding a Confederate submarine which sank during the Civil War appears to have been solved.
The pioneering vessel, dubbed the H.L Hunley, is credited as the first submarine to successfully down an enemy ship, but that historic moment now appears to have been the cause of its demise.
While out at sea in 1864, the Hunley attacked and sunk the U.S.S. Housatonic and then promptly vanished shortly thereafter.
Incredibly, the submarine was not seen again for another 131 years, when the vessel was found intact on the seafloor off the coast of South Carolina in 1995.
After the famed craft was raised from the water in 2000, it was donated to the state of South Carolina for historic preservation and study.
And, after several years of examination by experts, researchers now believe that they know what caused the vessel to sink.
Learn about their findings at the Coast to Coast AM website.