A remote community in northern Ontario is devastated after a mother and four children were killed in a house fire.

There is no word on what caused the early morning fire on the Kitchenuhmaykoosib Inninuwug First Nation, located about 600 kilometres north of Thunder Bay, Ont.

According to The Canadian Press, the woman had another older daughter who was away when the fire broke out.

Chief Donny Morris said every member of the community of roughly 1,000 was affected. “We are in utter disbelief,” he said in a statement. “Today, our community mourns this tragic loss.”

The victims were a single mother and four of her children, aged six, seven, nine, and 12.