PORTLAND, Ore. (AP) -- The Latest on a house fire in rural Oregon that killed four children (all times local):

11:50 a.m.

The fire chief in a rural Oregon town says a house fire that killed four children and critically burned three other people was caused by a portable space heater.

Riddle Fire Protection District Chief Rich Holloway said Thursday on the fire district's Facebook page that the fire was caused by combustible materials placed too close to the heater.

The authenticity of the post was confirmed by City Manager Kathy Wilson.

Holloway says a component of the family's fireplace that circulated heated air back into the house had malfunctioned several days before.

The family bought the space heater to stay warm until they could get the fireplace repaired.

Four children ages 4 to 13 died in the blaze.

Thirty-nine-year-old James Keith Howell, 38-year-old Tabitha Annette Howell and 13-year-old Andrew Hall-Young are in critical condition at a Portland hospital.