Obersteurmann Helmut Klotzch of U-175 yells to the crew of USCGC Spencer (WPG-36) for rescue after the cutter sank his U-Boat on April 17, 1943. U-175 was only five days into her third patrol when she was vectored with twenty-three other U-boats towards convoy HX-233. The convoy departed New York, United States on April 6 and contained fifty-eight merchants and twenty-one escorts of Escort Group A3 under to Captain Paul R. Heineman of Spencer. The U-boats sighted HX-233 at 2133 Hours Convoy Time on April 16. The next morning, while Spencer, HMS Diantbus, and later HMCS Skeena were chasing down sonar contacts, U-628 torpedoed SS Fort Rampart at 0605, which was abandoned and later sunk by the Allies. At 1150, Spencer, who had rejoined HX-233, established sonar contact with U-175. Attacking with two depth charges, Spencer then waited for the convoy to pass her position before attacking again at 1217. USCGC Duane joined Spencer in the hunt; then at 1238 the conning tower of U-175 broke the surface. In a hail of fire from both cutters and the tail end ships of HX-233 (which wrecked Spencer's motor launch and killed Spencer's Radioman Julius T. Petrella), U-175 was severely damaged. U-175's commander Korvettenkapitan Heinrich Bruns (April 3, 1912 - April 17, 1943) was killed. The crew opened the flood valves and abandoned ship. Spencer launched a rowboat with a boarding party under Lieutenant Commander John B. Oren that succeeded in entering the conning tower but could not stop the flooding. As U-175 sank by the stern, forty-one German sailors were rescued by Duane and Spencer. At 1630 the first Consolidated B-24 Liberator bomber from Northern Ireland arrived over HX-233, prompting the Kriegsmarine to call off further attacks. U-175's survivors were taken to Scotland on April 20, 1943.