Monterey, CA- The Monterey Fire Department said county residents need to check their heaters during the winter months after two people were found dead Monday because of carbon monoxide poisoning.

The cause remains under investigation but is

believed to be accidental, firefighters said.

According to the Monterey County coroner, a wall-

mounted gas heater appears to have played a

significant role in their deaths.

The two people killed has been identified as 53-

year-old Raymond Carlson and 60-year-old Ruth

Ann Carlson, both of Monterey.

Officials added that with the cold winter

temperatures, people who are using their heat-

producing products and equipment should make

sure that are properly working.

Carbon monoxide is poisonous gas that kills about 500 people in the U.S. each year.

It’s often known as the “silent killer” because people cannot hear, taste, see or smell the gas —unlike odorized natural gas.

Firefighters said residents should have a qualified professional inspect fuel-burning appliances at least once a year and install carbon monoxide alarms in the home.