At 22.20 hours on 22 Feb 1943, U-606 attacked convoy ON-166 and torpedoed three ships, the Empire Redshank, Chattanooga City and Expositor. The U-boat was lost after the attack.

The Chattanooga City (Master Robert C. Forbes) was struck by one torpedo in the center of #4 hold. The explosion bodily lifted the ship out of the water, blew off the hatch covers of the #3 and #4 holds, tore deck booms away and probably severed the main shaft. She quickly listed to starboard and settled rapidly. The order to abandon ship was given two minutes after the hit and water reached the welldeck one minute later. The ship sank by the stern in about 15 minutes. The ten officers, 27 crewmen and 21 armed guards (the ship was armed with one 4in, one 12pdr and six 20mm guns) cleared the ship in four lifeboats and one raft. They were picked up three hours later by HMCS Trillium (K 172) (T/Lt P.C. Evans, RCNR). The armed guard officer and ten of his men were transferred to USCGC Spencer (WPG 36) and landed in Argentia, Newfoundland on 27 February. The remaining survivors were landed at St. John’s on 26 February.