Two women died of apparent carbon monoxide poisoning Monday afternoon at their home in Lindstrom, Minn., about 35 miles northeast of the Twin Cities, authorities said.
The Lakes Area Police Department was called by the employer of one of the women who was concerned after not having heard from her for several days, the Associated Press reports.
When officers arrived, they could see through the window a woman slumped over on a couch. They forced the door open and determined she was dead. They also found a second woman in the house and she was also dead. The women, aged 53 and 56, lived together in the home, according to WCCO.
The Lindstrom fire department and Xcel Energy were called to the scene and found "extreme levels" of carbon monoxide in the home, and the furnace had stopped working.
Authorities found the furnace's exhaust pipe was blocked with soot and ice, WCCO reports.
The first police officer at the scene was treated at a hospital for carbon monoxide exposure and later released. The victims have not yet been identified.
The case is still under investigation.
Earlier this winter a father and daughter died of carbon monoxide poisoning, and two other family members fell ill, in their home just outside of Duluth. At that time authorities issued a public reminder to Minnesotans to be aware of the dangers of carbon monoxide, especially during the winter, and to install CO monitors in their homes.
Minnesota law requires homes have at least one operational CO alarm within 10 feet of every room legally used for sleeping, the state health department says.
About 170 people in the U.S. die each year from non-automotive carbon monoxide poisoning, the Consumer Product Safety Commission says. (Include all sources, and the number of fatalities jumps to about 400, according to the CDC.)