In the spring of 2021, Linda Brandmiller was working at a San Antonio arena converted into an emergency shelter for migrant children. Thousands of boys slept on cots as the Biden administration grappled with record numbers of minors entering the United States without their parents.

Ms. Brandmiller’s job was to help control sponsorships and she had been trained to research potential traffickers. In the first week, two cases jumped out at her: a man told her that he was sponsoring three boys to employ them in his construction company. Another, who lived in Florida, was trying to sponsor two children who would have to work to offset the cost of getting them north.

She immediately contacted supervisors working with the Department of Health and Human Services, the federal agency responsible for these children. “It’s urgent,” she wrote in an email seen by The New York Times.

But a few days later, she noticed that one of the children was going to be handed over to the man in Florida. She wrote another email, this time asking a supervisor for “immediate attention” and adding that the government had previously sent a 14-year-old boy to the same sponsor.

Brandmiller also emailed the manager of the shelter. A few days later, he was denied access to the building during his lunch break. She claims that she was never informed of the reasons for her dismissal.

Over the past two years, more than 250,000 migrant children have arrived in the United States alone. Thousands of children have found themselves in arduous jobs across the country – working nights in slaughterhouses, replacing roofs, operating machinery in factories – all in violation of child labor laws, such as a recent investigation by the Times has shown. After the article was published in February, the White House announced policy changes and a crackdown on companies that hire children.

Time and again, senior officials and contractors have reported to the Department of Health and Human Services, including in reports to Secretary of State Xavier Becerra, that children appear to be in danger. The Ministry of Labor issued press releases reporting an increase in child labor. Senior White House officials have received evidence of exploitation, such as groups of migrant children working with industrial equipment or caustic chemicals.

As the administration struggled to empty shelters that were overstretched, children were released with little support from sponsors who expected them to accept back-breaking and dangerous jobs.

In interviews with The Times, officials expressed concern for migrant children, but dismissed responsibility for failing to protect them.

Health Ministry officials said the department has enough control over sponsorships, but it cannot control what happens to children after they are released. The control of workplaces falls, according to them, within the competence of the Ministry of Labour.

Ministry of Labor officials said inspectors had focused more on child labor and were sharing information about workers with Health, but clarified that this was not a social welfare agency.

White House officials said that while the two departments had passed on information about migrant child labor, the reports were not considered urgent and did not clearly indicate the extent of the problem. White House spokeswoman Robyn M. Patterson said in a statement that the administration is now strengthening oversight of employers and reviewing its oversight of sponsorships.

“It is unacceptable for companies to use child labor, and this administration will continue to work to strengthen the system to investigate these violations and hold offenders accountable for their actions,” the statement read. .

“If I had seen it, they might have made the connection,” said Brandmiller, who is also an immigration lawyer. “There were so many opportunities to connect these elements. A spokesperson for the Department of Health and Human Services said the agency had no record of Ms Brandmiller’s concerns. The company that ran the emergency shelter declined to comment.

Ms Brandmiller said she was still worried about 14-year-old boy Antonio Diaz Mendez.

Antonio lives in Florida City, Florida, far from his family in Guatemala. During an interview last summer, he was sitting on the moldy porch of a house crowded with other migrant children. He explained that he worked long hours in a cold store, packing vegetables for distribution across the country, and that he had not seen his sponsor in months.

He missed his grandmother and sometimes went days without speaking to anyone. He wanted to go to school, but felt trapped because he had to earn money to pay off his debts, support himself and help his siblings.

According to him, no one has ever come to hear from him.

Antonio Diaz Mendez arrived at the border shortly after turning 14 and spent several weeks in a reception center before settling in Florida.

Shortly after President Joe Biden took office, the growing number of migrant children sparked tensions between the new administration and longtime officials.

The president had promised to abide by a 2008 anti-human trafficking law, which requires the federal government to accept children traveling alone from most countries and allows them to remain in the United States during the application process. legal status, which lasts for years.

But the law did not foresee that a pandemic would ravage the economies of Central American countries. Increasingly poor parents have begun sending their children to the United States to earn money, in a phenomenon that some immigration advocates call “voluntary family separation.”

In 2021, as images of children sleeping under life-saving blankets at overflow centers dominated the news, White House domestic policy chief Susan E. Rice expressed her frustration to members of her staff, according to five people who have worked with her. Ms Rice spoke out in a note she scribbled on a memo detailing the position of human rights advocates, who believed that a pandemic-era border closure forced parents to send their unaccompanied children, sometimes referred to as “UC” (Unaccompanied Children).

“That’s hogwash,” Ms. Rice wrote, according to a copy of the memo reviewed by The Times. “What leads to ‘voluntary’ separation is our generosity towards unaccompanied children!” »

In a statement, White House spokeswoman Robyn M. Patterson said any suggestion that Ms. Rice felt constrained by the requirements of the law was false and that she was “proud to do what she does.” and to treat children with dignity and respect”.

By law, the Department of Health and Human Services is responsible for monitoring sponsorships to ensure that they ensure the well-being of children and protect them from trafficking or exploitation.

Longtime Health Ministry staff have complained that the changes put children at risk. White House aides and administration officials expressed exasperation, saying these workers were clinging to protocols that kept children in residential centers when it was best for them to be. in a household with an adult.

“It was infuriating,” said Vivian Graubard, a White House adviser who worked with Ms. Rice on issues relating to migrant children.

At least five Health Ministry staff have filed complaints and said they were pushed out after raising questions about child safety.

Jallyn Sualog was the longest-serving member of the Department of Health’s division dealing with unaccompanied migrant children when Mr. Biden took office. She had helped set up the program after the 2008 law was passed and, as a lifelong Democrat, had rejoiced in Mr. Biden’s victory.

But soon she started hearing reports that the children were being handed over to adults who had lied about their identities or were planning to exploit them.

In an email from 2021, she warns her superiors: “If nothing is done, there will be a catastrophic event. She continued to send emails about situations she described as “critical” and “putting children at risk.”

Fearing that no one would listen to her, Ms. Sualog filed a complaint in fall 2021 with the Office of Inspector General of the Department of Health and Human Services, the agency’s internal oversight body, and asked for whistleblower protection. She also took the unusual step of speaking to congressional staffers about her concerns.

At the end of 2021, she was dismissed from her position. She filed a complaint with the federal bureau responsible for enforcing whistleblower protection rules, arguing that she had been the subject of unlawful retaliation.

Last fall, the Inspector General’s office released a report on Ms. Sualog’s case and several agency demotions and firings that “may have reached the level of whistle-blowing crackdowns.”

Ms Sualog reached a settlement with the agency, which agreed to pay her legal costs, and resigned last month.

A spokesperson for the Department of Health declined to comment on Ms Sualog’s complaint, but said the agency was not taking retaliatory action against whistleblowers. Although some staff members disagreed with the administration’s approach, the spokesperson said significant changes were needed to deal with the increase in the number of unaccompanied migrant children.

Even as seasoned employees left, others continued to sound the alarm. In January, shortly before the publication of the Times investigation, employees sent another memo to their bosses at the Department of Health, claiming that the system had resulted in dangerous discharges. “We are removing humanity from health and social services,” they wrote.

Some of the most persistent warnings that children were being directed into dangerous jobs came from outside government. The Department of Health releases most children to their sponsors without follow-up, but it hires organizations to provide thousands of high-risk children with support services for several months.

Last spring, Matt Haygood, senior director of children’s services for the United States Committee for Refugees and Immigrants, one of the largest of these organizations, sent several Department officials an email with the subject line ” Trafficking Concerns”.

“We have seen disturbing trends in the Chicago metro area,” he writes, including vans picking up children at odd hours, suggesting they are being driven to factory jobs. Mr. Haygood asked if the Ministry was considering adding the neighborhood to a watch list, so that potential sponsors would be vetted there more closely.

A Ministry staff member responded that more than 200 children, mostly Guatemalan, had recently been released into the neighborhood and confirmed that many of these cases had been marked as suspicious: adults were sponsoring several children and minors worked instead of going to school.

“There are certainly many other red flags regarding human trafficking,” the staffer wrote. Ms. Haygood expected the agency to add additional safeguards for children released in the Little Village area. Instead, the Ministry decided they weren’t necessary.

In response to The Times, a spokesperson for the Department of Health said the department had already put in place protections for released children on a few city streets and that at the time it considered the extension of these measures was overstated.

Other social service organizations said they too have spotted clusters of suspected cases, including in Nashville, Tennessee, and Dallas, Texas.

“We’re waiting for the congressional hearing to ask how all these kids got to this point,” Haygood said. Over the past two months, leaders of both parties in Congress have questioned why so many migrant children end up in exploitative jobs and two scrutiny hearings are scheduled for the House of Representatives on Tuesday.

A Health Ministry spokesperson said the Ministry was aware that some migrant children were working long hours because they were under great pressure to earn money, but the agency’s legal responsibility to respect for children stops once they are released. Nevertheless, the Ministry is working to provide a few months of case management for all unaccompanied migrant children, she said.

For now, most children in the care of sponsors have only limited support, apart from a Ministry of Health helpline.

In a call last year, a child living in Charlotte, North Carolina, said his sponsor got him a job at a restaurant and told him “he had to work to eat.” In another appeal, a child said his sponsor never enrolled him in school after he was released from a shelter in El Paso, Texas, and was forcing him to pay his rent and food.

The ministry spokesperson said the agency was asking local law enforcement to check when children were likely to be in danger.

White House domestic policy chief Susan E. Rice was at the heart of the migrant child crisis. As she lobbied for children to leave shelters more quickly, clues began to emerge about what happened to them once they left.

In the summer of 2021, at the height of the influx at the border, officials from the Ministry of Health issued a memo expressing concern over mounting reports of children working alongside of their sponsors, a sign of possible labor trafficking. This note reached Ms. Rice and her team.

Around the same time, the team was made aware of concerns about a large group of children who had been released from custody in a town in Alabama, according to six current and former staff members. The situation has received frequent updates, with the Department sending case managers to the city to check on the children’s health and coordinating with the Department of Labor and Homeland Security Investigation Services. to check if they worked in poultry factories.

A former senior White House adviser recalled thinking at the time that this development was concerning and suggested other cases might be overlooked.

A White House spokesman denied that senior officials had been briefed on the situation.

A few months later, according to a former senior White House official, Ms. Rice’s office learned that the Department of Health was unable to reach a growing number of migrant children just a month after their birth. release.

Tyler Moran, Mr. Biden’s senior migration adviser at the time, said she defers to the Department for how to assess information, such as the note from concerned Department officials and appeals to children who remained unanswered. Staff members, she said, had not highlighted a broader child labor crisis. “The White House was relying on agencies to let us know when there really was a problem,” Ms. Moran said.

The Ministry of Labor was also sending signals. In 2022, investigators began uncovering signs of migrant child labor in industrial workplaces, including several auto parts factories in the South. The Ministry issued press releases warning of an increase in child labor violations.

Last summer, labor investigators launched a major operation at a sanitation company that ended up discovering that more than 100 mostly Spanish-speaking children were working night shifts in meatpacking plants across the country. country.

As investigators discovered more and more migrant children working for the cleaning company across the country, the Department of Health and Human Services kept Ms. Rice’s team regularly updated on the situation for several months, according to two people familiar with these conversations.

The Department of Labor also included details of the cleaning business and auto parts operations in weekly cabinet-level reports. It was like, “We’ve got problems here,” said Martin J. Walsh, Secretary of Labor until last month. “We were sending reports to the White House, so they knew we were working on these issues. »

When the Labor Department updated its public dashboard in December, it showed a 69% increase in child labor violations since 2018.

A Labor Department spokesperson said the White House was aware of the increase in child labor because it was widely publicized. But Andrew J. Bates, White House deputy press secretary, said officials were unaware of the rise in child labor until The Times’ February report.