Relatives discovered the family members’ bodies Saturday evening in their south Moorhead home. Officials with the Ramsey County Medical Examiner’s Office in St. Paul said blood samples showed a lethal level of carbon monoxide, police said in a press release.
Police Chief Shannon Monroe said there is no indication of any kind of criminal activity and all signs point toward "some type of accidental situation."
Monroe said the carbon monoxide came from either the home's furnace or a van in the garage. Technicians couldn't find a defect in the furnace that would have sent carbon monoxide into the home.
Investigators found that a carbon monoxide detector in the garage had been removed and replaced with a smoke-only detector.
The two-story twin home did not have a basement and all the bedrooms were upstairs. The furnace was in a separate room inside the garage.
Monroe said the victims were wearing light clothing, indicating that the heat had been working. By the time first responders arrived, the temperature was 54 degrees in the house and only the furnace fan was on.
Five of the victims were found in their beds. Belin Hernandez and Marleny Pinto were on the floor in the bedroom area. Residents in the adjoining unit had no signs of carbon monoxide sickness, police said.
The family members, who had immigrated from Honduras, have been identified as Belin Hernandez, 37; Marleny Pinto, 34; Eldor Hernandez Castillo, 32; Mariela Guzman Pinto, 19; Breylin Hernandez, 16; Mike Hernandez, 7, and Marbely Hernandez, 5. They all lived together, police said.
Moorhead is on the Minnesota border next to Fargo, North Dakota, in a metropolitan area of about 230,000 people.
The Associated Press contributed to this report.