A second inmate has died inside a north Alabama Department of Corrections facility this week.

Clarence Jackson was found unresponsive in his cell at Limestone Correctional Facility on Sunday, according to ADOC spokesperson Kelly Betts. Jackson was taken to the prison’s health care unit “where all life-saving measures were unsuccessful,” she said.

Jackson, 34, was serving a 28-year sentence for murder and rape out of Montgomery County.

It’s the second death at the north Alabama prison this week. Another 34-year-old, Kenyon Arrington, died Saturday after he was beaten by a fellow inmate, ADOC said Monday.

Arrington was serving a 20-year sentence at Limestone Correctional Facility for a rape that happened in Crenshaw County. He was also taken to the prison’s health care unit, where he later died.

The ADOC Law Enforcement Services Division is investigating both deaths, and ADOC said more information would be available following that investigation. The department did not comment further on the two deaths, nor say if they were related.