▶ Watch Video: Two whistleblowers allege migrant children face poor living conditions at Fort Bliss

The Department of Health and Human Services’ (HHS) internal watchdog on Monday announced an investigation into federal employees’ concerns about a tent camp in Texas housing unaccompanied migrant children in U.S. government custody.

Led by investigators at the department’s Office of Inspector General, the probe is the first public government investigation into the emergency HHS housing site at Fort Bliss, the largest U.S. facility ever established to hold migrant children.

The tent camp inside the Army base has come under withering criticism from advocates amid reports of subpar conditions, limited services, prolonged stays and mental health issues among boys and girls housed there.

CBS News reported in June that incidents of self-harm, panic attacks and escape attempts among teenagers alarmed federal officials who worked at the site. Four whistleblowers who worked at the facility have also detailed concerns about filthy conditions, inadequate mental health services, lax coronavirus mitigation efforts and unqualified contractors caring for hundreds of minors.   

The HHS Office of Inspector General said its review will focus on reports of subpar case management, the service that allows migrant children to be released to family members in the U.S., and how that affected the well-being and safety of minors at Fort Bliss.

“We take seriously the concerns raised by individuals regarding the quality of case management at the Fort Bliss Emergency Intake Center and the potentially negative impact on children’s health, safety, and well-being,” said Tesia Williams, a spokesperson for the inspector general’s office. 

If investigators “obtain information about conduct that appears to fall outside of the law or HHS policies and regulations, we will forward those details to our Office of Investigations for appropriate action,” Williams continued.

A photo provided by a source shows migrant children walking outside tents inside a camp at Fort Bliss, Texas.

Obtained by CBS News

Officials said the review will be based on interviews and “on-site observations,” noting the Office of Inspector General expects to release its findings later this year.

A federal government volunteer who worked at the Fort Bliss site said the investigation needs to be thorough and focused on accountability. 

“I hope this will be a true investigation so that all the issues that countless federal volunteers reported will be corrected and the individuals that ignored the issues are held responsible,” the federal employee, who requested anonymity to speak candidly, told CBS News. “At the end of the day the vast majority of federal volunteers had the interest of the children in mind.”

The tent city inside Fort Bliss, which can currently accommodate up to 4,000 teenagers, is one of more than a dozen emergency housing sites the Biden administration set up at convention centers, work camps and military facilities to house children who crossed the southern border without their parents.

The emergency facilities allowed the Biden administration to get unaccompanied children out of overcrowded Border Patrol facilities in the spring and most have already closed. But the Fort Bliss tent camp and three other sites have remained in operation.

As of Friday, HHS was housing 14,000 migrant children, most of them at traditional shelters, which have licenses to care for minors, unlike Fort Bliss and the other emergency sites. 

HHS did not immediately comment on the investigation announced on Monday. The department has previously said it made improvements at Fort Bliss, including by instituting new training for staff and expanding case management and mental health services.

“The care and well-being of children in our custody continues to be a top priority for HHS,” the department said in a statement last week. “It remains our policy to swiftly report any alleged instances of wrongdoing to the appropriate authorities.”

White House press secretary Jen Psaki highlighted these improvements during a press briefing Monday, saying the administration is taking the matter “quite seriously.”

“Some of the reports of conditions are several weeks old or even longer than that, so there have been steps that have been taken to make improvements on the ground,” Psaki told CBS News chief White House correspondent Nancy Cordes.

Leecia Welch, who represents migrant children in a federal court case, welcomed the internal review, saying the HHS Office of Inspector General should oversee a “detailed investigation” into access to mental health services and educational and recreational activities for minors at Fort Bliss, as well as their overall safety.

“We first visited the national embarrassment that is the Fort Bliss emergency intake site over three months ago and we have been sounding the alarm ever since,” Welch, a lawyer at the National Center for Youth Law, told CBS News. “While there have been some improvements, it remains an awful place to send any child.”