Caribou was built in 1925 at Rotterdam, the Netherlands, for the Newfoundland Railway.Launched in 1925, she had a capacity of 3,000 horsepower (2,200 kW) and was able to reach a speed of 14.5 knots (26.9 km/h; 16.7 mph) when fully loaded. She also had steam-heat and electric lights in all of her cabins, which were considered to be a luxury at the time. Also, due to her ice-breaking design, Caribou also assisted during the seal hunt along the Newfoundland coast each spring.
The German submarine U-69 was patrolling the Gulf of St. Lawrence. It was a dark evening, and the heavy smoke from Caribou's coal-fired steam boilers silhouetted her against the nighttime horizon. At 3:51 a.m. Newfoundland Summer Time, on 14 October 1942, she was torpedoed approximately 37 km (20 nmi) southwest of Port aux Basques and sunk five minutes later.Grandmère spotted the submarine and tried to ram her, but, U-69 quickly submerged. Over the next two hours, the minesweeper dropped six depth charges, but did not damage the submarine, and U-69 crept away into the Atlantic undetected. Following procedure, Grandmère then went back for survivors. In the days after the sinking, the Canadian naval vessel was criticised in the Sydney Post-Record and The Globe and Mail – as well as other media outlets – for not immediately stopping and helping save survivors; but that was against operating procedures, and would have placed her in immediate danger of being sunk as well. After picking up survivors, Grandmère sailed for Sydney because it had better hospital facilities than Port aux Basques.
Caribou was carrying 46 crew members and 191 civilian and military passengers. The ship's longtime Captain, Benjamin Taverner, was commanding the vessel as she was struck, and perished along with his sons Stanley and Harold, who served as first and third officers respectively. Of the deceased, two were rescued at first, but they later died from exposure to the cold water. 137 people died that morning, and the passenger and crew totals were broken down as follows: of 118 military personnel, 57 died; of 73 civilians, 49 died; of the 46 crew members, 31 died. 34 bodies were found and brought to Port aux Basques by fishing schooners chartered by the Newfoundland Railway Company. To prevent rumours, the Royal Canadian Navy allowed the Sydney Post-Record and other media outlets to report the sinking, almost as soon as it happened, one of the few times that war censorship was temporarily lifted in this period. The sinking made front-page news in both The Toronto Daily Star and The Globe and Mail newspapers later that week.
In 1986, the CN Marine/Marine Atlantic ferry MV Caribou was named after SS Caribou. She plied the same route as the original ferry, travelling between North Sydney and Port aux Basques. On her maiden voyage, 12 May 1986, the ship stopped at the location where its predecessor sank. At approximately 5:30 a.m., survivor Mack Piercey, one of 13 survivors on board for the occasion, tossed a poppy-laden memorial wreath into the ocean and then the ship continued on to Port aux Basques to complete the voyage.
In 2014, as part of a special dedication service in the town of Port Hawkesbury's Veterans Memorial Park, SS Caribou's passengers and crew were honoured. Part of the dedication service included the unveiling of the anchor from the decommissioned MV Caribou as a new feature for the memorial.
Sub-Lieutenant Margaret Brooke (she would retire as a lieutenant commander) was a Royal Canadian Navy Nursing Sister who survived the sinking of SS Caribou. She and a colleague, Sub-Lieutenant Agnes Wilkie, clung to ropes on an overturned lifeboat until hypothermia caused SLt Wilkie to lose consciousness. SLt Brooke held onto the lifeboat with one hand and her unconscious friend with the other until daybreak when, despite her best efforts, a wave pulled SLt Wilkie away. For her selfless act, SLt Brooke was named a Member of the Order of the British Empire. In 2015, the Government of Canada announced that the second of the Harry DeWolf-class offshore patrol vessels building as part of the Arctic and Offshore Patrol Ship project would be named HMCS Margaret Brooke.
Caribou was featured on a 2c Newfoundland postage stamp in 1926.
In the Canadian series Bomb Girls, Caribou is mentioned to have sunk the previous day and give the people of the home front a good shock.
Rohwer, Jürgen; Hümmelchen, Gerhard (1992). Chronology of the War at Sea 1939–1945. Derek Masters (trans.) (2nd revised, expanded ed.). Annapolis, Maryland: Naval Institute Press. ISBN978-1-55750-105-9.