At 10 p.m., on 12 September 1942, was on patrol off the coast of western Africa, midway between Liberia and Ascension Island. The submarine's commanding officer, Werner Hartenstein, spotted the large British ship sailing alone and attacked it. Armed ships—which meant most merchantmen and troop transports—constituted legitimate targets for attack without warning. Armed as such, the "Laconia" fell into this category, and at 10:22 p.m. she transmitted a message on the 600 m (500 kHz) band: "SSS SSS 0434 South / 1125 West Laconia torpedoed." "SSS" was the code signifying "under attack by submarine". Additional messages were transmitted, but there is no record these were received by any other vessel or station.