Paramedics were called to a home on the 1600 block of South Wilton Street around 8:30 p.m. Saturday.
Police said the caller reported that the baby was acting strange.
Medics took the child to Children's Hospital. Police said the baby died several hours later.
The Special Victims Unit has launched an investigation into the child's death and police are at the house with a search warrant Sunday morning.
Police said while the investigation is ongoing with SVU, it does not appear that the death is suspicious at this time.