Empress of Ireland

I am trying to determine when and how my GGrandfather Karl Martin Henriksen traveled to the US. I have always been told he came across on the Empress of Ireland and took the Canadian Railway across Canada and landed in MT. 1920 cencus records indicate he immigrated in 1914. So ummm the Empress of Ireland sank in a huge disaster (1,012 lives lost) in May 1914. My mother didn't even know this, which is so odd . I looked at earlier passenger lists from that year and cannot find him. Any thoughts on how to locate his passenger record?