According to Chicago police, the boy entered the lake in the 1200 block of W. Jarvis at around 6:09 p.m.
He was underwater for an extended amount of time, when he was pulled out of the water and transported to St. Francis Hospital in critical condition.
The boy, identified as Fred Elouga, was pronounced dead Thursday at 12:32 p.m. at Lurie Children's Hospital, according to the Cook County Medical Examiner.
Area Detectives said they are investigating this as a death investigation at this time.