May 13, 1942 the Gulf Oil Company tanker Gulfpenn was plying the waters of the Gulf of Mexico en route from Port Arthur, Texas to Philadelphia, Pennsylvania. About six miles astern another Gulf Oil tanker, Gulfprince, was struck by a torpedo at 0640 (C.W.T.) and damaged, but did not sink. Captain Hodges of Gulfpenn left the area fearing an attack on his ship, but what he did not know is that there were at least two enemy submarines in the area.

At 1450 (C.W.T.) about 72 miles south of Pilottown, Louisiana the torpedo Hodges feared struck his ship aft in the engine room. The torpedo was fired by U-506 from shallow water, but it was enough to sink the tanker and her 90,000 barrels of much needed oil. Twelve men in the engine room were killed by the explosion, but twenty-six men, including one who was badly wounded, made it into the lifeboats before the ship sank.

The submarine did not surface and was not located either before or after the attack. A navy plane had flown over the area two hours before Gulfpenn had arrived, but due to the muddy conditions off the mouth of the Mississippi it was not sighted. The survivors were picked up SS Telde at 1730 (C.W.T.), but by then the wounded man had succumbed to his injuries. The men were landed at Pilottown and later transferred to Naval Station New Orleans.

Kapitänleutnant Erich Würdemann, commanding officer of U-506, was later awarded the Ritterkreuz, but perished in July of 1943 when U-506 was sunk by U.S. aircraft off Spain.