St. Charles officials say the incident occurred Monday in O’Fallon at the home of Vincent Celano.

Celano, his 11-year-old son, a 41-year-old nephew and the nephew’s 14-year-old son were sick and passed out because of the carbon monoxide.  Celano says another nephew showed up just in time, realized what was happening and called 911.

The St. Charles County Ambulance District says those in the house likely would have died if they had been in the house for another hour or two.

The problem was blamed on a dirty, 33-year-old furnace. The home did not have a carbon monoxide detector.

The four relatives were treated at a hospital.

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