Federal and state investigators are working at a West Allis house where three bodies were found following a fire.
Agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives and the state Department of Justice arrived Friday at the burned out home.
Rescue crews found the bodies of the three victims Thursday night.
Neighbors told the Milwaukee Journal Sentinel at least four young children lived in the house, including twin boys. Authorities haven't yet identified the victims.
The fire comes less than a month after another deadly fire in West Allis. Two young boys died when a home caught fire in the middle of the night. Two other boys escaped.