Billy MacMillan was a Canadian hockey player from Charlottetown, Prince Edward Island, who died aged 80 on July 15, after several years with the Canadian national team, including playing in two World Championships and the 1968 Winter Olympics, winning a bronze medal, MacMillan made his NHL debut in 1970 with the Toronto Maple Leafs . He played for the Toronto, Atlanta Flames and New York Islanders between 1970 and 1977, and retired in 1978. He became a coach during his senior year, spent the CHL Minors, and moved to the NHL in 1979, when he became an assistant coach of the Islanders. He was named head coach of the Colorado Rockies in 1980, also serving as general manager the following season. MacMillan remained with the team when they moved in 1982 to become the New Jersey Devils, and was released early in the 1983-84 season.
https://www.nj.com/devils/2023/07/devils-mourn-death-of-former-coach-billy-macmillan.html