A 78-year-old woman and her dog found dead in a Berrien County home over the weekend may have died of carbon monoxide poisoning caused by a car left running inside a garage.

Anna Bacchiocci, 78, and her dog were found by her son and daughter-in-law just after 5:30 p.m. Sunday, Aug. 7, Berrien Springs Oronoko Township Police said.

Investigators found that there were deadly levels of carbon monoxide in the home which may have came from a vehicle that was accidentally left running in the attached garage. Police have not found other sources of carbon monoxide inside the house.

Bacchiocci’s son and daughter-in-law, two police officers and two firefighters were treated at the scene for carbon monoxide exposure after they were in the house in the 4900 bock of Appian Way. Four of those individuals were also decontaminated because they may have been exposed to other chemicals.

They were released at the scene.

Police are still investigating Bacchiocci’s death.