The Michigan City Police Department said officers responded to a 911 call in the 2200-block of Normandy Drive around 7:15 a.m. Sunday.
The unresponsive child was taken to Franciscan Hospital. From there, he was flown to Comer Children's Hospital for advanced medical treatment.
The child died just after 7 p.m. Sunday, police said. The Cook County Medical Examiner's Office identified him as Augustus Williams.
A search warrant was executed at the home where Williams was found unresponsive.
Authorities did not immediately provide further information.