Police in Ohio say the deaths of five people, including three children, do not appear to be accidental.
Toledo police spokesman Joe Heffernan said all of the bodies were found in a garage Monday afternoon.
Firefighters used a sledge hammer to break into the garage that had been barricaded shut at the Toledo home.
Investigators think all five may have died from carbon monoxide poisoning.
Heffernan said officers were called to check on those inside the house after getting a call from a concerned family member.
Lucas County coroner, Dr. James Patrick, told The Toledo Blade that the five dead are a 54-year-old woman, her grandchildren, ages 10, 7, and 5, and a 32-year-old man, who is an uncle of one of the children.
Police say the children were primarily living with their grandparents but their parents were in the process of getting full custody of the children.
Police believe this was a murder-suicide.