It remains unclear how the man ended up in the water.
Firefighters said witnesses called 9-1-1 at around 1:30 p.m. to report they saw a man, walking along the lake's icy shore, fall into the water.
However, police said witnesses told them the man was running.
“Did the ice give way? Did the mean slip off the edge and into the water? That’s not clear," said CBC reporter Jay Turnbull from the scene.
Two witnesses being treated for nervous shock
Police boats and divers remain at the scene.