At 10.02 hours on 9 May 1942, the unescorted Lubrafol (Master E. Van Schoenberg) was torpedoed by U-564 about 3.5 miles off Hillsboro Inlet, Florida. A torpedo hit on the starboard side amidships at #5 tank, which burst into flames immediately and seconds later the #1 tank also caught fire. The explosion stopped the engines, destroyed the radio antenna and the foremast toppled on the bridge, killing two men. The survivors among the 38 crew members and six armed guards abandoned ship in three lifeboats, but one of them caught fire and the men had to jump overboard and were lost. The remaining two boats with 31 survivors, seven of them injured, were towed free from the burning tanker by two US Coast Guard boats and landed at Boynton Beach, Florida. The vessels also recovered seven bodies.

The burning Lubrafol drifted until 11 May and then sank in shallow waters. The burnt out wreck was broken up in 1954.