A malfunctioning furnace leaked carbon monoxide into a Weisenberg Township home Thursday, killing a 90-year-old woman who lived there, according to the Lehigh County coroner’s office.

Mary Emma Werley of 7996 Claussville Road was pronounced dead at her home and her death was ruled accidental, Coroner Scott Grim said. Authorities did not say what caused the malfunction.

According to county dispatchers, a trooper on patrol notified the Communications Center that he saw smoke coming from the home around 11 a.m. Weisenberg Fire Chief Scott Freeman said his department was called to assist the state police by using a fan to ventilate fumes and smoke from the single-story home next to Hope Community Church.

He said there was no fire when his department arrived.

About a half-dozen people, some in tears, were at the home but did not wish to comment.