PHOENIX (AP) – Arizona corrections officials are investigating the death of a female inmate who collapsed after spending nearly four hours in an outdoor holding cell on a day when the temperature hit 103.

Marcia Powell, who was serving a 27-month sentence for prostitution, was put in the uncovered chain-link cell at a state prison in Goodyear about 11 a.m. Tuesday.

She collapsed about 2:30 p.m. and died at a Phoenix-area hospital early Wednesday. Department of Corrections officials did not immediately explain why Powell was placed in the holding cell.

The department’s investigations unit has begun a criminal probe to determine whether corrections officials were negligent in their treatment of Powell.