The family of Jaleel R. Drayton, of Park Forest, called police shortly before 4 a.m. after they could not find him.
Jaleel, whose nickname was Ducky, was last seen playing with friends near Central Park where police and family searched on foot. A relative spotted his clothing near a pool in the Aqua Center and alerted police. An officer scaled a fence, pulled the boy out of the pool and immediately performed CPR.
Paramedics rushed the boy to Franciscan Health Olympia Fields, but he was later pronounced dead. It was not immediately clear when an autopsy would be performed.
Jaleel was not a strong swimmer, his family said, and it was immediately unclear how he got into the pool area.
Authorities are reviewing security camera video from nearby buildings.
Jaleel loved football and played for the Park Forest Hurricanes.
"He was just a good kid. It hurts," said his coach, Alvin Lacy. He added: "He was just a personable kid. You can't coach that. You can't teach that. It was just his personality."
The aquatic center, which has at least four large pools, is owned by the park district and managed by Jeff Ellis Management.
The Park Forest Aqua Center remained closed Tuesday.
The Illinois Crime Scene Investigation Unit responded to the scene to help Park Forest investigators process evidence.
Police offered their condolences to the boy's family in a statement released Tuesday morning.
"While any death is reason to grieve, the death of a child is particularly troubling, and the Park Forest Police Department offers its sincerest condolences to the loved ones and friends of the juvenile."