At 19.00 hours on 14 May 1942 the Amapala (Master Harold B. Christiansen) sailed from New Orleans and anchored at Pilottown about 01.00 hours on 15 May. At 12.00 hours she left the anchorage and cleared Southwest Pass around 13.30 hours. About 00.05 hours on 16 May, U-507 was seen coming up fast on the starboard quarter, about four miles away. The unescorted and unarmed Amapala was making 15 knots and was zigzagging at that time. The master immediately ordered a change of the course to put the ship´s stern to the U-boat and send out an SOS and SSS four times in position 26°40N/88°17W.

At 00.12 hours, U-507 began to attack the ship with the deck and machine guns and soon scored hits on the starboard side, destroying the lifeboat #3, wounding a fireman and throwing five men into the water. These men were picked up by the boat #4, which had been launched first, followed by two other boats. During this time, the Germans only fired with the AA guns and continued shelling the vessel after the crew had abandoned ship. About three hours after the attack an aircraft appeared, sighted the U-boat and unsuccessfully dropped depth charges. It remained in the area for an hour and then left.

The wounded fireman was placed in a lifeboat, but died at 04.00 hours and was buried at sea. In the morning a US Coast Guard aircraft spotted the lifeboats and directed the fishing schooner Gonzalez out of Mobile to the boats. Shortly after 16.00 hours, another US Coast Guard aircraft landed on the water and brought two injured men to the Pensacola Naval Hospital. The remaining survivors were picked up by the fishing schooner and were landed at Burrwood Naval Base at 15.00 hours on 17 May. The Amapala was still afloat when the survivors were picked up but her whole after deck was awash. She was taken in tow by USCGC Boutwell (WPC 130) but foundered in 26°30N/89°12W at about 24.00 hours on 16 May.