FORT DODGE, Iowa (AP) - Authorities are investigating the death of a 31-year-old inmate who was found unresponsive in his cell at the Fort Dodge prison. The Iowa Department of Corrections said Claude Middlebrooks was discovered on the floor of his cell at Fort Dodge Correctional Facility on Friday evening. A statement Monday said that prison employees responded and performed emergency medical procedures, including CPR. Fort Dodge emergency medical responders also were called. Middlebrooks was transported by ambulance to Trinity Regional Hospital, where he was soon pronounced dead. The department says the cause of death will be determined after an autopsy that will include toxicology testing, which could take four to six weeks. Middlebrooks was serving a 10-year sentence on a conviction for third-degree sexual abuse in Linn County. His sentence started in 2006.