MacLean, who made the announcement on air, planned to return to his home in Oakville, Ont., to be with his family. His mother had pancreatic cancer.

"I'm probably in that bubble of denial that you get in when you're involved in television, but the truth of the matter is I gave her all I had all my life so there's no harm in not having been there for the final moments," MacLean said near the end of the broadcast.

Scott Russell will take over his on-air duties from 6 p.m. to midnight for the duration of the Summer Games.