CHICAGO -- Police in Chicago are investigating the death of a nearly 5-week-old infant who fell off a third-story porch on Chicago's South Side.

Chicago Police Officer Michael Fitzpatrick says the baby who died early Monday had been in a car seat but was unrestrained at the time of the fall. Fitzpatrick says the baby's mother and father were arguing on an apartment porch in the East Chatham neighborhood, when the man kicked the woman in the back as she walked down stairs.

That's when the child fell from the railing.

The Cook County medical examiner's office identified the child as Jeremiah Range. Police say the baby was pronounced dead at University of Chicago Comer Children's Hospital.

Chicago police are performing a death investigation.