The former school bus driver, who pleaded guilty to 937 counts in July, was found hanged in his cell at an Ohio prison late Tuesday, a state corrections official said.

An autopsy on Wednesday confirmed the cause of death was suicide by hanging, said Dr. Jan Gorniak, the Franklin County coroner.

“This man couldn’t take, for even a month, a small portion of what he had dished out for more than a decade,” said Cuyahoga County Prosecutor Timothy McGinty, who agreed to a deal that spared Castro the death penalty in exchange for life in prison.

Castro had been taken off suicide watch while still in Cleveland’s Cuyahoga County Jail on June 5, a spokesman said, and his was the seventh suicide in Ohio prisons this year, according to the American Civil Liberties Union, which called for a full investigation.

State prison and county jail officials denied Castro permission to receive independent mental health counseling, even though he had contemplated suicide in 2004 and was likely to suffer depression after being sentenced to life in prison, his defense lawyers said.

“We were never provided any explanation” for being denied independent mental health care, defense attorney Craig Weintraub said. “We don’t know what the rational was to take him off suicide watch.”

Castro, 53, was sentenced on Aug. 1 to life plus 1,000 years in prison without the possibility of parole for abducting the three women and keeping them in the dungeon-like confines of his house, where they were starved, beaten and sexually assaulted.

The case captured international attention when it broke in May, as many people were elated by news the three women had been found alive, then stunned by the details of their ordeal.

Some $1.4 million in charitable donations poured in from 10,800 donors seeking to help the women resume their lives.

The house where the three were held, bound with chains and ropes for periods of time, has been torn down along with two neighboring abandoned homes, creating an extended vacant lot in the working-class neighborhood.

Castro was transferred to the Correctional Reception Center outside Columbus, the state capital, on Aug. 5 and was to remain there while undergoing mental and physical evaluation before being transferred to a permanent lockup, prison officials said.

He was in protective custody with guards checking on him every half hour and isolated from other inmates at the Correctional Reception Center in Orient.

Ohio prisons are at 130 percent capacity, a prison watchdog group says, and the Castro hanging closely followed that of Ohio death row inmate Billy Slagle, 44, who was found hanged in his prison cell on Aug. 4, three days before his scheduled execution. Results of an investigation had yet to be released.

Since 2000, suicide rates in Ohio prisons have remained mostly stable, generally ranging between four and seven deaths per year, according to the Correctional Institution Inspection Committee. The exceptions were 2004 and 2007, which each had 11.

‘ROT IN HELL’

Police initially arrested Castro’s two brothers, Pedro and Onil, but released them upon finding they had no links to the kidnappings. Reached by phone on Wednesday, Pedro Castro declined to comment.

“The last page has been turned,” said Julio Cesar Castro, uncle of the Castro brothers and owner of a general store in the neighborhood where the women were held.

The Castro family learned of his death from the media, attorney Weintraub said, and word spread quickly through the west Cleveland neighborhood.

“Rot in hell, Castro,” a woman passenger yelled from a white sport utility vehicle driving by the site on Wednesday, part of a slow but steady line of cars moving past a group of television trucks.

“I guess he couldn’t handle it. He took the coward’s way out,” said neighbor Walter Freeman, 57.

Castro was taken into custody in May, just after Amanda Berry, 27, Gina DeJesus, 23, and Michelle Knight, 32, were freed with assistance from neighbors who heard Berry’s cries for help.

Also rescued was Berry’s 6-year-old daughter, fathered by Castro and born during her mother’s captivity.

Police also recovered from the home a suicide note and confession he wrote in 2004. DM

Photo: Ariel Castro (C), 53, breaks down while talking about the child that he fathered with Amada Berry as he addresses the court while seated between attorneys Craig Weintraub (L) and Jaye Schlachet in the courtroom in Cleveland, Ohio August 1, 2013. REUTERS/Aaron Josefczyk