A 22-year-old man who was swimming with friends in a Brampton lake is dead after he began struggling in the water and drowned Saturday afternoon.

Peel Regional Police say Adriss Cheema of Brampton was swimming in Professor's Lake, at 1660 North Park Dr., when he began having trouble and disappeared under the water.

Horrified onlookers tried unsuccessfully to rescue Cheema, police said in a news release.

Police and Brampton Fire Department divers and boats searched the area until shortly before 8 p.m., when they recovered Cheema's body.

Police are warning citizens to exercise caution near water and swim only in designated areas. They also recommend having safety equipment within reach.

The spring-fed Professor's Lake was originally a gravel pit and is now used for sailing and fishing. It also has a beach for a designated swimming area.