From the Super Mario Wiki
Jack Westelmen, better known as Danny Wells (April 7, 1941 – November 28, 2013), was the Canadian character actor who portrayed Luigi in The Super Mario Bros. Super Show! live action segments and voiced the character in the cartoon segments. He played various other characters in the live-action series as well, such as Mario and Luigi's Aunt Luigeena and their cousin Luigi Bob. Wells worked opposite Lou Albano, who portrayed Mario in both the live action and animated segments.
24 years after the conclusion of The Super Mario Bros. Super Show!, on November 28, 2013, Wells died in Toronto, Canada at age 72.