At 00.22 hours on 21 September 1943, U-952 fired a Gnat at an escort of convoy ON-202 and heard a detonation after three minutes, followed by sinking noises. HMS Polyanthus (K 47) (Lt J.G. Aitken, RNR) was searching behind convoy for the attacker and the survivors of HMCS St. Croix (I 81) (LtCdr A.H. Dobson, DSC, RCNR) and sank immediately after being hit. The commander, six officers and 78 ratings were lost. The only survivor was SubLt F.J. Young, RNVR, being picked up by HMS Itchen (K 227) (Cdr C.E. Bridgman, DSO, RNR), but he died when the frigate was torpedoed and sunk two days later by U-666 (Engel).