From the AP story linked above:
If you have any suspicions about whether your appliances are producing excess carbon monoxide I have the equipment to test them, please stop by my office at 27 Store Road or call me at 475-2415 ext. 35 to arrange a test. Be sure you have a good quality carbon monoxide detector in your home, and check it often for proper operation. If you suspect you have high carbon monoxide levels in your home get fresh air immediately! Get everyone outside and seek medical help. Tragedies like this can be prevented, but only if people are aware of the danger.
Coleen Jennings' mother, Joanne Donald of Tower, told the Star Tribune of Minneapolis that she got a call from her grandson when he arrived home Saturday morning saying he couldn't find his mother and everyone was unconscious.
"Call 911," Donald recalled telling him. "Get out of there and get some fresh air before you get sick, too."
Donald's grandson, Gary Jennings, 20, and three Beltrami County sheriff's deputies went to North Country Regional Hospital in Bemidji after being in the house only briefly. The deputies were treated and released. Gary Jennings was released Saturday night, a nursing supervisor said.
According to the Star Tribune, Donald said authorities told her that the carbon monoxide apparently came from a malfunctioning furnace. Beryl Wernberg, emergency management director for Beltrami County, told The Associated Press on Sunday that the source of the carbon monoxide was still under investigation.
"It's just such a tragedy," Donald, 73, told the Star Tribune. "We are just trying to cope. We will be for a long time."
Her daughter had complained for days about being tired and nauseous, but Donald said, "We just figured it was the flu shots. ... We never once suspected it was carbon monoxide. The problem probably peaked on Friday night."
Donald said she felt lucky her grandson had spent the night at a friend's house.
"What would have happened if nobody came to the house in the morning?" she wondered.