Topp's sinking of the has cast a shadow on his conduct in action. When he spotted the coastal steamer off Chincoteague, Virginia on 3 April 1942, he surfaced "U-552", overtook it from astern, and, without offering the Captain the chance to surrender, attacked it with his deck gun from 600 yards, firing a total of 93 rounds. Captain Bill Webster was killed in the shelling. "Atwater's" civilian Merchant Marine crew of 27 suffered 24 lost lives during the attack. According to one account, when United States Coast Guard Cutter number 218 "Legare" appeared, it found the ship sunk with only several feet of its mast still visible. Bodies were seen, including one in a lifeboat riddle with machine gun holes. There is no direct evidence he machine-gunned defenseless crewmen, and nothing in Topp's otherwise stellar career or postwar actions suggest he was capable of such an act.