STEPHENS COUNTY, Okla. (KFOR) – The Oklahoma State Bureau of Investigation is investigating after officials say a Stephens County Jail inmate discovered another inmate dead.

According to the Stephens County Sheriff’s Office, an inmate discovered another alone in a cell unresponsive on Christmas Day.

That inmate immediately began life-saving measures, but the other person was already deceased, OSBI officials say.

The Medical Examiner’s Office will determine cause and manner of death.

The deceased inmate was arrested in August for failing to appear in court on a manslaughter charge.

No other information is available at this time.