Upper Darby, PA – Three people were hospitalized after a carbon monoxide leak inside an Upper Darby home.

The incident occurred around 2 p.m. Sunday on the unit block of Richfield Road.

Officials say a water heater malfunctioned inside the home.

Police were notified after a disoriented person walked outside, asked for help and collapsed.

Upon arrival, they found two more people inside the home.

They were all taken to a local hospital for treatment.

The investigation is ongoing.