BESSEMER, Ala. (WIAT) — Two inmates at William E. Donaldson Correctional Facility in Bessemer died within a few hours of each other Wednesday.

According to the Jefferson County Coroner’s Office, Allen Dewitt Bibbs was found unresponsive in his cell at 3:33 a.m. By 3:50 a.m., he was pronounced dead. Bibbs, 48, was serving a life sentence for a kidnapping charge out of Houston County in 2009.

At 6:33 a.m., Calenes Jones was found unresponsive in the prison infirmary, where he was being treated for an undisclosed “significant natural disease.” By 6:43 a.m., he was pronounced dead. Jones, 42, was serving a life sentence for a robbery and assault conviction out of Jefferson County in 2008.

The last death at Donaldson was Earnest Charles McReynolds, 69, who was found unresponsive in his cell on May 10 and was pronounced dead later that day in the infirmary.

On Thursday, the Alabama Department of Corrections will perform autopsies on both Bibbs and Jones to determine the causes of their deaths. Both deaths are under investigation.