An Arizona inmate who died after spending nearly four hours in the desert heat was left in an outdoor holding cell for twice as long as she should have been, the state prisons director said Wednesday.

Three corrections officers have been put on paid leave while the state investigates Wednesday's heat-related death of Marcia Powell, who was left in her unshaded cell in 103-degree heat at a prison in Goodyear.

"The death of Marsha Powell is a tragedy and a failure," prisons director Charles Ryan said. "The investigation will determine whether there was negligence and will tell us how to remedy our failures."

Powell, who was serving a 27-month sentence for prostitution, was placed alone in the cell while being moved to an onsite detention unit. Ryan said officers placed Powell in the cell after a disturbance at the detention unit, but he would not elaborate on the nature of the disturbance.

Officers gave Powell, 48, bottled water, as required under prison policy, Ryan said. Corrections officers were 20 yards away in a control room while she was in the cell. Investigators will try to determine how much water she was given and whether she drank it.

Officers did not remove her after two hours as they should have done under department policy, Ryan said at a news conference.

"It is intended to be temporary," he said. "It is not intended to be a place where they are held for an inordinate amount of time."

The criminal probe, conducted by the Corrections Department's investigations unit, will seek to determine whether officials were negligent in their treatment of Powell, who collapsed at 2:40 p.m. Tuesday and died later at a hospital.

Ryan said he hopes to release a report into Powell's death by late next week. The Maricopa County Attorney's office will then decide whether to charge the corrections officers involved.

Ryan would not release the names or disciplinary records of the deputy warden, captain and lieutenant placed on paid leave.

He said he told all state prison wardens to monitor the temperatures at outdoor holding cells while they are housing inmates.

Powell is the 79th person to die in state prisons since July 2008, according to Ryan. He said most of the deaths were from natural causes, but there were three suicides and one murder.

Corrections officials were unable to locate family members for Powell.