Firefighters discovered five members of a family dead inside a Toledo, Ohio, garage Monday. Police believe the cause of death was due to carbon monoxide poisoning -- and not accidental.

Police discovered the victims inside the garage around 3:15 p.m., reports The Associated Press. According to Joe Heffernan of the Toledo police department, the police responded to a call from a relative who was worried after not hearing from the family.

Dr. James Patrick, the Lucas County coroner, said the victims are be a 56-year-old woman, a 32-year-old man, a 10-year-old girl, a 5-year old girl and a 7-year old boy, reports the Toledo Blade. The  woman was the grandmother to the three children, and the man was their uncle. No names were given.

No motive has been determined, although the police believe the deaths were not accidental. The police also did not disclose how they came to that conclusion, notes the Toledo Blade. The police are currently examining the garage for clues.

There have been no further details released at this time. According to WNWO, police have not disclosed if the house had a working carbon monoxide detector.