World War 2 investigators have solved one of the conflict's most baffling mysteries following the discovery of an allied submarine in Japan. Researchers have found the final resting place of the USS Albacore, a US Navy ship credited with sinking at least 10 enemy ships during her service before disappearing just months before the end of the war. The discovery has given families of the fallen final closure, with the fate of their loved ones left unconfirmed until now.