An early-morning carbon monoxide scare in Etobicoke has prompted an investigation by Toronto Fire Services after one person was rushed to hospital in serious condition.

Emergency crews were sent to a house on Taysham Crescent, near Kipling Avenue and Finch Avenue West, shortly before 2 a.m. Monday. The call was initially reported as a medical emergency, but once on scene, firefighters detected dangerous carbon monoxide levels inside the home.

Paramedics transported one occupant to hospital, while two others were checked over at the residence and did not require further treatment.

Fire crews stayed at the property alongside technicians from Enbridge Gas to trace the source of the gas and make sure the home was safe.

The cause of the leak has not yet been determined. Officials are reminding residents that carbon monoxide is invisible and odourless, and stress the importance of having properly functioning detectors installed on every level of a home, particularly close to sleeping areas.