by Sarah Childress

The riots that broke out this weekend at a Texas prison featured in a 2011 FRONTLINE investigation erupted after years of complaints from inmates about poor conditions and abuse at the facility, and at least one previous protest.

Prisoners at the Willacy County Correctional Institution, most of them convicted for immigration or nonviolent drug offenses, set fire to the Kevlar tents where they are housed in a protest over medical care, according to the federal Bureau of Prisons (BOP).

The bureau said the prison was now “uninhabitable,” and Management and Training Corp. (MTC), the private company contracted to run the facility, said that all 2,834 inmates will be transferred to other facilities by the end of the week.

“It was certainly a predictable uprising, given the way in which BOP turned a blind eye to conditions at Willacy and other prisons,” said Carl Takei, a staff attorney at the ACLU National Prison Project who has been investigating conditions at the facility.

MTC spokesman Issa Arnita said that the BOP has dozens of monitors at the facility who ensure that inmates are well treated “in all aspects.” Those monitors are responsible for reporting any concerns to prison officials for correction. Arnita didn’t say whether BOP monitors had flagged any problems at Willacy. “Those are details that will come out in the full investigation,” he said, which the company will launch once the inmates are relocated.

In 2011, FRONTLINE uncovered more than a dozen allegations of sexual abuse by guards at the facility in Lost in Detention, as well as physical and racial abuse. At the time, Willacy was run by MTC for U.S. Immigration and Customs Enforcement (ICE). The facility housed people who had not yet been convicted, but were awaiting immigration hearings. Guards were accused of harassing women for sexual favors, and in some cases sexually assaulting them. Other detainees were beaten by guards who cursed them with racial epithets.

That year, ICE transferred its detainees from Willacy, and handed control of the facility to the Bureau of Prisons. The bureau allowed MTC to keep the contract.

New allegations later surfaced. In June 2014, the ACLU issued a report on Willacy and four other privately run prisons in Texas, and found the inmates there are subject to abuse and mistreatment, and prevented from connecting with their families.

At Willacy, inmates are crammed 200 at a time into squalid Kevlar tents, with no private space, the report found. Insects crawl through holes in the tents. The open toilets regularly overflow with sewage, and in 2013 several inmates camped out in the yard in protest. “They treat us like animals,” one person told the the civil-rights group.

One inmate cited in the report said that some had talked about setting fire to the tents, but figured officials would just build them back up again.

“We completely disagree with and dispute” the ACLU allegations, Arnita, the MTC spokesman said, adding that they were merely anecdotal.

Watch Now: Lost in Detention