At 13.45 hours on 15 June 1944, HMS Mourne (K 261) (LtCdr R.S. Holland, RD, RNR) was hit and sunk by a Gnat from U-767 south-southeast of Wolf Rock, while on patrol off the western entrance of the English Channel together with other warships of the 5th Escort Group, including HMS Bickerton (K 466) (Cdr D.G.F.W. MacIntyre, DSO, RN) and HMS Kempthorne (K 483) (LtCdr A. Brown, RNR), to screen Operation Neptune, the Allied landings in the Normandy. The frigate had just turned towards the U-boat after making Asdic contact when the torpedo struck the bow and she disappeared in an explosion caused by the ignition of the forward magazine. The commander, seven officers and 102 ratings were lost and another rating later died of wounds.