Very sad, and the second carbon monoxide problem I've seen in 2 weeks;
a friend of ours was on the phone with my wife, and when my wife hung up, she said our friend was going to clean the soot off her walls; the furnace was acting up. I had her call her right back, and told her to turn off the furnace and call the service company right away; if the soot was getting in the house, so was the carbon monoxide.
She turned it off, and called; they were there in about an hour. They took some readings, and there was plenty of carbon monoxide in her house; but not enough to kill, yet. Her insurance company put in a new furnace, cleaned the soot, and now her kids have been "cured" of the colds/flu they were fighting over the last week.
FYI- get a carbon monoxide detector; they are cheap, reliable, and will save your life.