Three girls have died after a furnace leaked carbon monoxide in a home in Troy, Ohio, the Associated Press reported.
An 8-year-old boy who was also exposed to the toxic gas remains in the hospital in critical condition.
A relative found the four children unconscious on Friday and called 911, telling dispatchers that they had been sick for days. They lived in the rented home with their grandmother, who was in the hospital for treatment of pneumonia, the AP reported.
Dionanna Bishop, 14, and Dejah Bishop, 13, died on Friday. Their cousin Jakia Jones, 13, was pronounced dead on Sunday, and her 8-year-old brother, Jahari Ward, remained in critical condition.
Troy police told the Dayton Daily News that the deaths appeared to be related to a malfunctioning furnace. There were no carbon monoxide detectors in the home, and police were reviewing whether the landlords should face criminal charges.
An attorney for the home's owners said they have owned the property for about 20 years and had always promptly addressed maintenance issues, WHIO reported. The landlords were unaware of any problem with the furnace or that children were living in the home.