At 00.34 hours on 9 Feb 1942, U-654 fired three single torpedoes at convoy ON-60. Just as a hit on a corvette with the pennant number K 100 was observed, a second explosion took place beyond. A freighter of 7000 grt was seen to stop and was later attacked with a coup de grâce by the U-boat, but missed.

FFL Alysse (K 100) (LV Jacques Pépin Lehalleur) was hit on the port side in the foreship by one torpedo and settled by the bow about 420 nautical miles east of Cape Race, Newfoundland. 35 crew members and one British liasion officer were lost. The survivors, including the wounded commander, were picked up by HMCS Moosejaw (K 164) (T/Lt H.D. Campsie, RCNR) and HMCS Hepatica (K 159) (T/Lt T. Gilmour, RCNR) and landed at St. Johns on 11 February. The latter took the torpedoed corvette in tow by the stern because the forward bulkhead was still intact and it was thought that she could be saved, but the tow parted just after 30 minutes so HMCS Hepatica had to wait until dawn. At 11.00 hours, a boarding party went aboard and the tug HMS Prudent (W 73), escorted by HMCS Minas (J 165) was sent from Newfoundland to salvage the vessel. In the meantime HMCS Hepatica managed to take her in tow again but after 18 hours the weather got worse and the forward bulkhead of FFL Alysse gave away, causing her to sink after a boiler explosion in 46°34N/44°10W at 11.30 hours on 10 February.