Carbon monoxide poisoning is suspected in the deaths of a 39-year-old man and his 11-year-old daughter who were found in a large camper being used as a home by a family just north of Duluth, authorities said.

Two other siblings in the camper in Rice Lake Township, a 14-year-old boy and a 15-year-old girl, were taken by ambulance Wednesday night to Essentia Health-St. Mary's Medical Center in Duluth and then transferred to Hennepin County Medical Center for further treatment, the St. Louis County Sheriffs' Office.

An HCMC spokeswoman said the two teens were in critical condition Thursday afternoon.

Killed were Michael J. Mechley and Charlene Mechley, the Sheriff's Office reported. The surviving children were identified as Noah Mechley and Karley Mechley.

"It appears that the camper was their home" on property in the 4700 block of 5th Avenue S., said Sheriff's Lt. Jason Lukovsky.

It was one of the children who called their grandfather from inside the camper to report "there was a problem inside with the generator," Lukovsky said.

"Readings were taken, and there were high levels" of carbon monoxide, when emergency responders arrived on the scene, the lieutenant added.

Responders found a generator near the camper, and it was not operating when deputies showed up, Lukovsky said.

The county medical examiner's office has yet to reveal a cause of death for the man and girl.

Paul Walsh • 612-673-4482