MADISON, Wis. -

Madison firefighters said a newly installed carbon monoxide or CO detector likely saved a Madison man's life Thursday night.

According to a release, crews responded to the man's home to check on CO levels and found dangerous levels of the poisonous gas. 

Firefighters began ventilating the house immediately. According to the release, the cause of the leak was discovered by crews from MG&E, who said a 70-year-old furnace was to blame.

The CO detector was installed by MFD in December 2013. Anyone interested in installing detectors or smoke alarms can call MFD.