An inmate from the Graham County Jail was pronounced dead at the Mount Graham Regional Medical Center on Sunday after apparently suffering a massive heart attack.

Tommy Andris Serna, 37, of Fort Thomas was in the correctional facility while awaiting trial on DUI charges.

According to Jail Commander Tim Graver, Serna was a model inmate who had earned trustee status and was housed in the jail's Honor pod. His job assignments included cleaning up the jail's classroom and running the laundry room. "Staff and (the jail) population are taking it hard," Graver said. "He was one of those guys who always had a smile on his face; (he) always had something funny to say."

Graver told the Courier that Serna hurt his back Tuesday and was taken to the hospital. An evaluation concluded he had pulled some muscles in his back and, upon his return to the jail, he was placed in a private cell to rest.

A corrections officer made a welfare check on Serna about 5:30 p.m. on Sunday, and the inmate was coherent and talking but complained his back hurt, according to Graver. The officer dropped off some commissary forms and returned to find Serna lying on the floor unresponsive and not breathing.

The jail's nurse and other staff members performed cardiopulmonary resuscitation on Serna until they were relieved by paramedics from Southwest Ambulance.

The paramedics were able to get a pulse and transported Serna to the hospital. Graver told the Courier that Serna never regained the ability to breathe for himself, and his heart stopped several times at the hospital.

According to Ryan Rapier, the hospital's director of public relations, Serna was pronounced dead Sunday evening. Rapier corroborated Graver's assertion that Serna was found unresponsive at the jail and never regained consciousness.

The Pima County Medical Examiner will examine Serna and determine an official cause of death, but a doctor at MGRMC said it appeared that he suffered a massive heart attack, according to Graver.

Because Serna apparently died from natural causes, the jail is performing its own investigation into his death. If the medical examiner determines there were other contributing factors, the investigation will be handled by a different agency, most likely the Department of Public Safety.