NORTH HUNTINGDON, Pa. — Carbon monoxide poisoning is suspected in the deaths of an elderly couple, authorities said.

The bodies of Joseph and Freda Polinski, both 88, were found late Thursday night after a relative unable to contact them went to their North Huntingdon Township home, the Westmoreland County coroner’s office said.

Authorities said emergency responders confirmed carbon monoxide levels within the residence and fire department crews ventilated the home to allow investigators to process the scene.

Toxicology tests will take several weeks, the coroner’s office said.

Carbon monoxide is an odorless, colorless gas found in fumes produced by furnaces, stoves, lanterns and gas ranges, or by burning charcoal and wood. The gas can build up in enclosed or partially enclosed spaces.

Each year, about 50,000 people are taken to emergency departments due to accidental carbon monoxide poisoning, and more than 400 deaths are attributed to such exposure annually, according to the Centers for Disease Control and Prevention.