A young woman and two children are dead after a house fire on Wednesday in a remote Ontario First Nation.

Investigators with Ontario's Fire Marshall are in Wunnumin Lake First Nation today to help determine the cause of the fire.

All three of the dead are female — a 21-year-old, a six-year-old and a one-year-old. Their names are not being released until after a post mortem.

Nishnawbe Aski Police said another person was injured "as a result of several attempts to rescue the victims." He is reported to be in hospital in stable condition.

A news release from the First Nation says the community "has been devastated by this tragedy."

Crisis teams from surrounding First Nations are on their way to Wunnumin Lake to support those who are grieving.

About 600 people live in Wunnumin Lake, located 500 km north of Thunder Bay.