MINNEAPOLIS (WCCO) – Authorities in northern Minnesota say carbon monoxide poisoning is likely to blame for the death of a man and his dog in Duluth.

The St. Louis County Sheriff’s Office says deputies responded Thursday night to an unresponsive person following a call from one of the man’s friends.

READ MORE: Procession Outside Minnesota Capitol Honors Victims Of Domestic Violence

Deputies found 54-year-old Michael Steen and his dog dead in their home. Investigators say high levels of carbon monoxide were detected inside the house, adding that there were no carbon monoxide alarms inside.

Still, an autopsy will be performed to determine Steen’s cause of death.

Meanwhile, the sheriff’s office is advising residents to test their carbon monoxide detectors and replace them if needed.

READ MORE: GOP-Controlled Wisconsin Assembly To Vote On Tougher Penalties For Protesters

According to the Minnesota Department of Health, there were 14 carbon monoxide poisoning deaths in the state last year.

Carbon monoxide poisoning deaths tend to occur in winter, when the gas is given off by heating devices.

Carbon monoxide, or CO, has no odor, color or taste. CO poisoning symptoms include headache, dizziness, chest pain, vomiting and confusion.

MORE NEWS: Vikings Will Reportedly 'Work To Hire' Browns' Kwesi Adofo-Mensah As GM

According to the Centers for Disease Control, people who are asleep or drunk can die of CO poisoning before showing symptoms.