The Laconia incident was a series of events surrounding the sinking of a British troopship in the Atlantic Ocean on 12 September 1942, during World War II, and a subsequent aerial attack on German and Italian submarines involved in rescue attempts. RMS Laconia, carrying some 2,732 crew, passengers, soldiers, and prisoners of war, was torpedoed and sunk by U-156, a German U-boat, off the West African coast. Operating partly under the dictates of the old prize rules, the U-boat commander, KorvettenkapitänWerner Hartenstein, immediately commenced rescue operations. U-156 broadcast their position on open radio channels to all Allied powers nearby, and were joined by the crews of several other U-boats in the vicinity.
After surfacing and picking up survivors, who were accommodated on the foredeck, U-156 headed on the surface under Red Cross banners to rendezvous with Vichy French ships and transfer the survivors. En route, the U-boat was spotted by a B-24 Liberator bomber of the US Army Air Forces. The aircrew, having reported the U-boat's location, intentions, and the presence of survivors, were then ordered to attack the sub. The B-24 killed dozens of Laconia's survivors with bombs and strafing attacks, forcing U-156 to cast their remaining survivors into the sea and crash dive to avoid being destroyed.
Rescue operations were continued by other vessels. Another U-boat, U-506, was also attacked by US aircraft and forced to dive. A total of 1,113 survivors were rescued; however, 1,619 were killed – mostly Italian POWs. The event changed the general attitude of Germany's naval personnel towards rescuing stranded Allied seamen. The commanders of the Kriegsmarine were shortly issued the Laconia Order by Grand Admiral Karl Dönitz, which specifically forbade any such attempt and ushered in unrestricted submarine warfare for the remainder of the war.
The B-24 pilots mistakenly reported they had sunk U-156, and were awarded medals for their "bravery". Neither the US pilots nor their commander were punished or investigated, and the matter was quietly forgotten by the US military. During the later Nuremberg trials, a prosecutor attempted to cite the Laconia Order as proof of war crimes by Dönitz and his submariners. The ploy backfired and caused much embarrassment to the United States after the incident's full report had emerged.
RMS Laconia was built in 1921 as a civilian ocean liner. During World War II she was requisitioned for the war effort, and by 1942 had been converted into a troopship. At the time of the incident she was transporting mostly Italian prisoners of war from Cape Town to Freetown, under the command of Captain Rudolph Sharp. The ship was carrying 463 officers and crew, 87 civilians, 286 British soldiers, 1,793 Italian prisoners and 103 Polish soldiers acting as guards of the prisoners.