Pittsburgh police homicide and sex assault detectives are investigating the death of an infant boy this afternoon in Garfield.

Paramedics and police were called to the 5100 block of Columbo Street about 12:35 p.m. for a report of an unresponsive infant. When they arrived, an occupant of the apartment was giving the two-month-old boy CPR, according to police.

Paramedics pronounced him dead at the scene, though the cause of his death remains unknown. The Allegheny County Medical Examiner's office will conduct an autopsy on the boy to determine how he died.

An initial investigation revealed that the infant was asleep in a bedroom with his mother, who found the boy unresponsive when she awoke. Another adult in the apartment called 911.

Police said it is standard procedure for homicide and sex assault family crisis detectives to investigate child deaths.