BESSEMER, Ala. (WIAT) — Authorities are investigating the causes behind three inmate deaths last week at the William E. Donaldson Correctional Facility in Bessemer.

According to the Jefferson County Coroner’s Office, 73-year-old Don Robert Barclay was found unresponsive around 6:28 a.m. on Tuesday, July 7, inside the prison infirmary where he was being treated for an unspecified “significant natural disease.”

Barclay was serving a life sentence at Donaldson for a 1996 sodomy conviction out of Autauga County. 

Lionel Ferado Oneal, 45, was found at the facility around 6 a.m. Friday and was pronounced dead 30 minutes later. Oneal was serving a 25-year sentence for a 2012 manslaughter conviction out of Macon County.

Jakari Marquz Norris, 30, was found unresponsive on Sunday around 12:45 a.m. and pronounced dead at 1:14 a.m. He was serving a 10 year sentence for a 2014 robbery conviction out of Tallapoosa County.

The JCCO reports that autopsies performed in all three cases found no signs of trauma or foul play.

Joe C. Davis, a 75-year-old inmate at Donaldson, was found at the facility on June 23 and was transported to UAB Hospital for further treatment of “significant natural diseases.” He died at the hospital Friday night. Davis was serving a life sentence for 1991 robbery and assault convictions out of Jefferson County.

All of these incidents are being investigated by ADOC.