The incident took place around 2:30 a.m. Friday when an ambulance was sent to the apartment house at 104 Oak St. in Yonkers when a 10-year-old fainted, Cucolo said.
When fire units arrived on scene they found a high level of carbon monoxide throughout the building causing firefighters to don breathing apparatus as they searched for other victims, he added.
Nine residents were found and treated for high levels of carbon monoxide before being transported to Jacobi Hospital., he said.
A search of the apartment by firefighters and ConEd employees found a blocked chimney, causing two gas meters to be locked until repairs could be made.
"This could have been a deadly incident if not for the quick actions of Yonkers first responders, Empress and Con Edison," Cucolo said. "Make sure everyone has working carbon monoxide alarms near sleeping areas."
Click here to follow Daily Voice Mount Vernon and receive free news updates.