By CBS 2 Chicago Staff

CHICAGO (CBS) — An Evanston mother and father were waiting Monday night for what will likely be heartbreaking news.

They believe their son drowned in Lake Michigan. But since crews have not found him yet, he has not been identified.

READ MORE: Thieves Keep Using Postal Master Keys To Steal Mail: How Are They Getting A Hold Of Those Keys?

Emergency workers have been searching the lake near Monroe Harbor for the missing man since Sunday. The Police and Fire departments said the man fell off a boat.

An Evanston father believes that man is hi son, C.J. Weaver, 32.

READ MORE: Chicago Weather: Wednesday Starts On A Chilly Note

Weaver went boating in the area on Sunday.

The Chicago Police Department Marine Unit has used sonar to search for the victim.

MORE NEWS: View Live Radar

The Fire Department said Sunday evening that the search had transitioned to a recovery mission rather than a rescue mission, meaning it is believed that the man did not survive.

CBS 2 Chicago Staff