Post-war:
1955 sold to Germany and renamed Stephanitor for D. Oltmann & Co. 1960 converted to an ore carrier (11664 grt). Broken up at La Spezia in February 1963.

At 07.49 hours on 15 July 1942 the unescorted Pennsylvania Sun (Master Frederick Lyall) was hit by one torpedo from U-571 about 125 miles west of Key West, while steaming on a zigzag course at 14 knots. The torpedo struck amidships on the port side between the #5 and #6 tanks and blew away the port wing of the bridge, killed the quartermaster and a seaman and ignited the cargo. The master steered for five minutes southeast at full speed and then ordered the engines stopped, while a distress signal was sent and confirmed. The survivors among the nine officers, 33 crewmen and 17 armed guards (the ship was armed with one 5in, one 3in, four 20mm and two .30cal guns) on board abandoned ship in three lifeboats, rowed away and put out sea anchors to wait for a rescue vessel. They were picked up by USS Dahlgren (DD 187) after three and one-half hours and taken to Key West the same day.

The next evening, the master, three officers and the crew of USS Willet (ARS 12) returned to the Pennsylvania Sun, when a patrol aircraft reported that the fire had abated. They extinguished the flames and towed her to Key West, where temporary repairs were made. The tanker steamed under own power with her crew to Chester, Pennsylvania and returned to service after the permanent repairs were completed.