Following his death from liver cancer in Chicago in 1970, at the age of 40, he was interred in the Burr Oak Cemetery, Alsip, Illinois. Spann's grave laid unmarked for almost thirty years, until Steve Salter (president of the Killer Blues Headstone Project) wrote a letter to Blues Revue magazine to say "This piano great is lying in an unmarked grave. Let's do something about this deplorable situation". This lit a spark in the blues community on a world wide level. Blues enthusiasts from Alaska to Venezuela, from Surrey to England, and Singapore sent donations to purchase Spann a headstone. On June 6, 1999 the marker was unveiled during a private ceremony. The stone reads "Otis played the deepest blues we ever heard - He'll play forever in our hearts".