An inmate has died at a Kansas prison.

According to the Kansas Department of Corrections, Lansing Correctional Facility inmate George Eugene Phillips, 39, died Sunday.

Phillips was found unresponsive in his cell. Staff and Emergency Medical Service personnel administered life-saving measures but were unable to revive him. The cause of death is pending the results of an independent autopsy.

Per protocol, when a resident dies in the custody of the Kansas Department of Correction, the death is under investigation by the KDOC and the Kansas Bureau of Investigation. The investigation is ongoing.

Phillips was serving a 577-month sentence for convictions of aggravated kidnapping, aggravated robbery, and criminal threat in Sedgwick County, Kansas.

The Lansing Correctional Facility, formerly the Kansas State Penitentiary, opened in 1867. The facility only serves males and maintains maximum and medium units totaling 1,920 beds and a 512-bed minimum security unit.