A 10-month-old boy has died after an early morning carbon monoxide leak at a Barrie home.

Emergency crews were called to the home on Barre Drive Sunday morning. They arrived to find the 10-month-old in the house without vital signs. His 30-year-old mother was found unconscious and his two-year-old sister was found alert, but suffering from signs of carbon monoxide poisoning.

High levels of carbon monoxide were detected inside the home, Barrie Fire said.

All three were immediately rushed to hospital. The mother and sister were later airlifted to a Toronto area hospital.

Firefighters initially indicated there was some sort of detector in the home, but have since confirmed there were no working carbon monoxide detectors in the house.

Fire crews say it was the children’s father who discovered the scene when he came home from work.

Police say the boy's mother is in critical condition and her two-year-old daughter is in stable condition.

Both Barrie police and the Office of the Chief Coroner are investigating.