The USS Grouper was conducting operations in the South China Sea during World War II when it aimed to disrupt Japanese maritime supply lines. On October 1, 1942, while patrolling the area, the Grouper spotted the Japanese transport ship Lisbon Maru and launched a torpedo strike. Unknown to the crew of the Grouper, the Lisbon Maru was transporting British prisoners of war captured during the Battle of Hong Kong in late 1941. The ship had been repurposed by the Japanese to carry around 1,800 prisoners, subjecting them to perilous conditions aboard. The torpedo struck and ultimately led to the sinking of the Lisbon Maru, creating confusion and panic among the POWs on board. The aftermath saw many prisoners trapped in the maritime disaster, with scores losing their lives or struggling to survive in the water. As the Japanese military scrambled to manage the wreck and recover its personnel, the incident further cemented the theme of tragic miscommunication and the often-overlooked humanity of wartime struggles. The sinking remains a stark reminder of the brutal realities faced by both military personnel and civilians during the vast and tumultuous scope of the war. The event gained notoriety in subsequent accounts of naval warfare and the untold stories of POWs caught in the crossfire.