WATERTOWN (AP) - A mother critically injured in a weekend house fire that killed her two young children has died at a Twin Cities hospital.

The fire broke out Saturday morning at the family home in Carver County's Watertown Township. Police say the house was engulfed in flames by the time firefighters arrived. Eleven-year-old Tyler Nustad and 3-year-old Layla were found dead in the home.

Fire officials say 33-year-old Tia Nustad died after she was taken to Hennepin County Medical Center.

The cause of the fire remains under investigation.