The SS Princess Sophia was a steel-built coastal passenger liner in the coastal service fleet of the Canadian Pacific Railway (CPR). Along with SS Princess Adelaide, SS Princess Alice, and SS Princess Mary, Princess Sophia was one of four similar ships built for CPR during 1910-1911. On 25 October 1918, Princess Sophia sank with the loss of all aboard after grounding on Vanderbilt Reef in Lynn Canal near Juneau, Alaska. With 343 or more people dying in the incident, the wreck of the Princess Sophia was the worst maritime accident in the history of British Columbia and Alaska. The circumstances of the wreck were controversial, as some felt that all aboard could have been saved. Beginning in 1901, Canadian Pacific Railway ran a line of steamships on the west coast of Canada and the southeast coast of Alaska. The route from Victoria, BC and Vancouver, BC ran through the winding channels and fjords along the coast, stopping at the principal towns for passengers, cargo, and mail. This route is still important today and is called the Inside Passage. Major ports of call along the Inside Passage include Prince Rupert, BC; Alert Bay, BC; Wrangell, AK; Ketchikan, AK; Juneau, AK; and Skagway, AK.