Their day to cross the border eventually came. They intended to surrender to American border-patrol authorities on the other side and to seek asylum. The smugglers gave Flores and the others a set of small, flimsy rafts. They didn’t even have paddles—one person was supposed to swim in the water and pull the raft along with him. Things didn’t go as planned.

Read: Purgatory at the border

Partway through the crossing, Border Patrol agents showed up to intercept them. “Hide!” someone shouted. The migrants panicked. One immediately dove off the raft, flipping it over and tipping everyone into the water.

Flores had a sweatshirt tied around his neck, and it quickly soaked up water, dragging him down. “I couldn’t actually breathe,” he said, remembering the sensation of drowning.

Before he drowned, a Border Patrol officer pulled him out of the water and asked him how old he was. When Flores replied “14,” the officer turned pale and brought him onshore with the rest of the group of migrants.

Read: Today’s migrant flow is different

Flores was now in Border Patrol’s custody. But he was alive—and, most importantly, on American soil.

Flores is one of the thousands of children who came to the United States alone fleeing violence in Central America—a population that the federal government officially classifies as “unaccompanied alien children.” Over 200,000 children—mostly from El Salvador, Honduras, and Guatemala—have arrived since 2012, according to the Office of Refugee Resettlement. Almost 41,000 children arrived in 2017 alone.

The great majority, including Flores, go on to seek asylum once they arrive in the United States. Flores was one of the lucky ones. His asylum claim was processed and granted in a matter of weeks after his interview with the Arlington asylum office in 2015.

But now, the Trump administration is actively unraveling ways for asylum-seeking migrant children to stay in the United States. Asylum approvals have plummeted, and the administration wants to deny all asylum claims for all who cross the border illegally—something that advocates are calling an “asylum ban.” A federal judge blocked the policy on November 20, and litigation continues. The federal government announced on December 21 that asylum seekers will remain in Mexico while their decisions are pending, and it is likely that advocates will challenge that policy change as well.

Although asylum has always been difficult for children to win, this outright hostility toward asylum seekers has not always been the case. In 2008, recognizing that unaccompanied migrant children faced specific humanitarian concerns compared with adults, Congress established a channel through the Trafficking Victims Protection Act for unaccompanied migrant children to seek asylum. But the burden is still on the children to argue their case in a way that fits the law’s protections.