SS Santa Rita was a refrigerated cargo ship built for the United States Maritime Commission by Federal Shipbuilding of Kearny, New Jersey in 1941. Operated by the Grace Line, Santa Rita en route from Cape Town to Charleston, South Carolina, when she was attacked by on 9 July 1942. Steaming on a non-evasive course at northeast of Puerto Rico, a single torpedo from U-172 hit the ship in the near the engine room. The explosion destroyed the engines; opened a hole in the hull of the ship, which immediately flooded the No. 3 cargo hold; and killed one officer and two men. After ten minutes, the ship's master, Henry Stephenson, ordered the ship abandoned; most of the surviving officers and crew and the ship's two passengers had already boarded the Nos. 3 and 4 lifeboats.
When the boat did not immediately sink, U-172 fired machine gun bursts at the vessel to discourage her crew from returning. The U-boat got off four quick shots with her deck gun that struck Santa Ritas superstructure, but did not finish off the ship. After taking Stephenson prisoner aboard the submarine, crewmen from U-172 boarded the still-floating Santa Rita and searched the ship for two hours, finally emerging with some scavenged food. After seven more shots from the deck gun were fired, Santa Rita rolled over on an even keel and sank at 15:20 near position . American destroyers and rescued most of the survivors and landed them at Port of Spain, Trinidad, while another boat rescued the rest and took them to Puerto Rico. Stephenson was repatriated to the United States in February 1945.