A 10-month-old boy is dead after he was found unconscious in his Barrie home early Saturday morning, suffering from carbon monoxide poisoning.

Barrie firefighters said a man came home to find his wife and a 10-month-old infant unresponsive and his 2-year-old child alert, but showing signs of carbon monoxide poisoning.

Barrie police confirmed to CTV News Barrie that the infant boy was pronounced dead later on Saturday.

Emergency crews were called to the home and the three were rushed to a local hospital. The mother and young girl have since been airlifted to a Toronto-area hospital.

The mother is in critical condition and the girl is in serious but stable condition, police say.

High levels of carbon monoxide were detected when firefighters entered the Barre Drive home, Barrie Fire said.

There was no working carbon monoxide detector in the home, firefighters said.

Enbridge and Barrie police are investigating at the home.