PITTSBURGH — Police are trying to find the mother of a 3-month-old baby abandoned outside a Pittsburgh home wearing only a diaper.

Investigators said the child was left on a doorstep in the city’s East Liberty neighborhood on Monday night.

A passer-by stopped after hearing arguing and retrieving the baby. Jonetta McCowan told a TV station the child was left on the home’s front porch after a dispute. McCowan told the station she bundled the child in her clothes and took him to police.

Investigators said the child was taken to a hospital in good condition. Police Commander RoShelle Brackney said the child was in serious danger because of temperatures that hovered around 20 degrees.