At 11.54 hours on 9 Oct 1942 the unescorted Coloradan (Master Robert Hugh Murphy) was hit on the port side by one torpedo from U-159 while steaming on a zigzag course at 9.5 knots about 200 miles southwest of Capetown. The torpedo struck the vessel between the #5 and #6 hatches and destroyed the bulkhead between the holds, blew out the double bottom and damaged the shaft alley. The watch below secured the main engines as the ship quickly settled and sank by the stern within eight minutes. The crew of nine officers, 30 men and 15 armed guards (the ship was armed with one 4in, one 3in, four 20mm and two .30cal guns) launched two lifeboats and all four rafts, but two rafts drifted away before they could be used. Six crew members failed to leave the ship. The U-boat surfaced shortly afterwards and went to the boats for questioning. The third mate answered questions concerning the ship and cargo and the Germans gave him the course and distance to land and wished them a pleasant voyage and good liberty. All survivors were divided equally among the two boats and sailed together until they were separated on the afternoon of 10 October. The next day, the master and 22 men in one boat were picked up by HMS Active (H 14) (LtCdr M.W. Tomkinson, RN), which searched unsuccessfully for the other boat and then landed the survivors in Capetown on 14 October. On 19 October, the other boat in charge of the chief mate with 25 men reached the coast and was towed by a fishing boat to Thorne Bay, South Africa. One day later these survivors were taken to Capetown, where many required hospitalization.

15 of the survivors were later repatriated on the Zaandam, which was sunk by U-174 (Thilo) on 2 November. Six crewmen from the Coloradan died.