Two children died overnight when a fire broke out in the family home in the suburb of Donnacona, about 50 kilometres west of Quebec City.
Firefighters discovered the bodies of two girls, aged nine and 15, in different rooms on the second floor of the home.
Their parents and three other children were taken to hospital with burns and smoke inhalation.
They likely suffered additional injuries, because some of them jumped out a second-storey window to reach safety.
While Surete du Quebec investigators have not yet determined the cause of the fire, they discovered that two smoke detectors in the house were not working.
A town grieves
Mayor Andre Marcoux says the town of the town of 6,000 is overwhelmed by the tragedy.
He said the deaths were especially tragic because the 15-year-old had tried to rescue her little sister.
In the wake of the tragedy, the town's residents -- and people from all over Quebec -- have rallied to support the surviving family members.
Marcoux says they will be able to help find a new home for the family, and provide them with furniture, clothing and money.
