TROY, Ohio (AP) — A third child has died after being found in an Ohio home where there were high levels of carbon monoxide.

13-year-old Jakia Jones died Sunday.

Her cousins 14-year-old Dionanna Bishop and 13-year-old Dejah Bishop died Friday after a relative found them unconscious inside a home in Troy. Her 8-year-old brother, Jahari Jones, is in critical condition.

Police say a furnace caused the leak of carbon monoxide, an odorless and colorless gas created when some fuels are burned. The relative reported to police the children had been sick for days. The children lived with their grandmother, who was hospitalized with pneumonia Friday.

An attorney for a couple who own the home says they weren’t aware of furnace problems and didn’t know children lived there.