At 07.35 hours on 13 Jul, 1942, the unescorted R.W. Gallagher (Master Aage Petersen) was hit on the starboard side by two torpedoes from U-67 about 80 miles from Southwest Pass, Mississippi. The first torpedo struck at the #3 tank just forward of amidships and the second hit abaft the midships house between the #8 tank and the pump room. The explosions buckled parts of the ship and started a fire that quickly spread the length of the vessel and into the water. The tanker immediately took a 30° list to starboard, capsized at 09.00 hours and sank at 11.30 hours.
With the steam whistle jammed, the eight officers, 32 crewmen and twelve armed guards (the ship was armed with one 5in, one 3in, two .50cal and two .30cal guns) abandoned ship in one lifeboat, one raft and by jumping into the water because the fire had destroyed the other boats and rafts. The master was the last man that jumped overboard after he waited for 40 minutes on the bow. Two officers, four crewmen and two armed guards were lost.
The survivors were picked up within one hour by the US Coast Guard cutter USS Boutwell (WPC 130) and three of the most seriously wounded were taken by a US Coast Guard plane from Biloxi Air Station to Lake Pontchatrain, transferred to the US Coast Guard boat USS CG-6264 and taken to the Marine hospital in New Orleans. Two crewmen died ashore from severe burns after reaching the hospital.