Between 07.07 and 07.09 hours on 10 Sep 1941, U-432 fired three bow torpedoes and one stern torpedo at ships in convoy SC-42 and observed one ship sinking in two minutes and a hit on another ship. The ships hit were Winterswijk and Stargard.

The Stargard (Master Lars Larsen) was hit amidships in the engine room by one torpedo. The explosion tore open the bridge deck and destroyed both port lifeboats and caused a heavy starboard list when the ship settled by the stern with the entire midships section enveloped in steam. Two men on watch below were killed and the master and two crewmen were thrown overboard, but were rescued by a starboard lifeboat, which had been launched by three men. The remaining survivors stayed on board and were soon thereafter taken off by the Norwegian steam merchant Regin. The men in the boat were picked up after 30 minutes by a corvette and landed in Reykjavik on 13 September, where the master and two crewmen were taken to a hospital. The ship was last seen about two hours after being torpedoed, lying on her starboard side.