At 01.56, 01.59 and 02.06 hours on 12 May 1942, U-124 fired torpedoes at the convoy ONS-92 southeast of Cape Farewell and observed hits on three ships. At 02.22 hours, U-124 made a second attack and observed one hit amidships after 1 minute 56 seconds. Mohr claimed three ships totalling 16.100 tons sunk. However, only two ships were hit at the time of the first attack, the Empire Dell and Llanover.

The master Hugh Mackinnon, 38 crew members and seven passengers (RAF personnel) from the Empire Dell were rescued. 25 survivors were picked up by the Canadian corvette HMCS Shediac (K 110) (Lt J.E. Clayton) and landed at St.Johns, Newfoundland on 17 May. 21 survivors were picked up by the British rescue ship Bury (Master Lawrence Edwin Brown OBE) and landed at St.Johns on 16 May. Two crew members were lost.