RUPERT, Idaho (KLIX) – A Magic Valley inmate’s death is under investigation.

Thomas M. Rettew, 38, of Rupert died at Cassia Regional Hospital around 11 p.m. Thursday, according to a statement by the Cassia County Sheriff’s Office on Friday. He was incarcerated at the Mini-Cassia Criminal Justice Center.

The Twin Falls County Sheriff’s Office, as part of the Critical Incident Task Force, is investigating the incident. No further statements by the justice center will be made about the death pending the conclusion of the investigation, according to the sheriff's office.