A carbon monoxide alarm is being credited with helping an Owen Sound family escape safely.
The family called 9-1-1 after hearing the alarm go off around 7:30 Tuesday morning.
Owen Sound Fire and Emergency crews rushed to an east side home.
Four people were inside the home at the time, two were taken to hospital by ambulance for precautionary reasons.
Firefighters went inside to record carbon monoxide levels and it registered readings of 50 to 100 parts per million.
Crews from Union Gas and the Fire Department have determined that the cause of the carbon monoxide was from the home's furnace.
The house was immediately ventilated.