Police say the official cause of death for the three people who died in a house fire in Barron last month was smoke inhalation.
That confirms the results of a preliminary autopsy of the father and his two children.
The Wisconsin Department of Criminal Investigation is handling the case.
Police Chief Joe Vierkandt says the victims had no injuries unrelated to the fire and toxicology test results are pending.
Vierkandt says it could be weeks before the official cause of the fire is determined.
A woman who was in the house at the time survived.
No names have been released.