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A group of Central American migrants is questioned about their children's health after surrendering to U.S. Border Patrol ...

What I saw happening at the U.S.-Mexico border

Editor’s Note: PBS NewsHour correspondent Amna Nawaz and her team have been reporting from both sides of the southern border. This is her first-hand account of what she saw.

The desert and sky both stretch as far as the eye can see in parts of San Luis, Arizona. For our PBS NewsHour team — producer Rachel Wellford, cameraman Michael Werner, and news assistant Gabriela Martinez — it can feel like a world away from Washington, D.C., where the immigration debate rages on. But the front lines of that fight are here, where the U.S. meets Mexico in what’s known as the Yuma Sector of U.S. Customs and Border Protection’s Border Patrol.

The Yuma Sector consists of 126 miles of border. For years the barrier here has been held up as the gold standard for border enforcement — heavy, triple-layer fencing, plus technology, plus additional manpower. But in the last three years, border patrol agents have seen a surge in the numbers of families and unaccompanied children crossing. It’s not the volume that’s taxing their system, they told us, it’s the demographics.

WATCH: At U.S.-Mexico border, migrants seeking legal entry are stranded in hazardous ‘limbo’

Border Patrol’s processing and detention centers were designed and constructed to hold single, adult men for a maximum of 12 hours. Today, because of the rules and challenges of caring for different populations, those same centers are holding families and children — including toddlers and infants — for 72 hours or longer. The agency shared with us a photo of a little girl, a toddler, whose mother was in the hospital and who was inconsolable when she was with other children at the facility. A Border Patrol agent made a makeshift bed of blankets next to his desk, so the girl could sleep and play away from the group.

Officials say they devoted the equivalent of six full-time agents just to addressing the medical needs of these families and children last year — agents, they argue, that should be out doing enforcement work.

Border Patrol agents didn’t allow us to record any videos or take photos inside the detention area. And I can understand why. It was difficult to reconcile that the scene inside the detention area was unfolding in the U.S. A pregnant woman sleeping on a thin pad in a cement cell, the toilet a few feet away behind a half-wall. Dozens and dozens of teenagers and boys, lying head-to-foot in another cramped room, tripping over each other to move. Babies in their mothers’ arms, seeing the rest of the world only through the single, thick pane of glass from inside their cells.

Officials here are candid about their frustrations. They say they requested a trailer as spillover space for the kids to play. They were twice denied. Meanwhile, the families keep coming. So we went to the Mexican side of the border to meet them on their journey.

Just a few yards from the U.S. port of entry, the line begins. Plastic tarp after plastic tarp, shielding family after family from the hot, midday sun. There are 253 families on the day we visit; more than 1,000 people, including hundreds of young children. They’ve been living on the streets, sleeping on the sidewalk, praying their funds don’t run out, while they wait for their chance to legally enter the United States.

WATCH: How surge in family border crossings is complicating enforcement

An informal list — a notebook, filled with the names, ages, and home cities of each family waiting — is kept at the front of the line. Every family we spoke to said the same thing. There was nothing for them back home. They are desperate for work, stability, and security. A better life for their children. They want to enter the U.S. legally, and they couldn’t afford to pay smugglers the going rate of $6,000 to help them cross illegally anyway. So they’ll wait.

U.S. officials said they are processing an average of one family a day — some days more, some days none.

Some are hopeful; they’ve made the arduous journey, survived for weeks on the streets, and believe their uncertainty will end when they’re allowed to enter the U.S. Some are fearful; one mother, down to her last 200 pesos – just more than $10 — breaks down as she confesses she has no plan for how she’ll feed her family, or buy her son the cold medicine he needs. So far, she’s lived off the kindness of others in the line. And like the others in the line, she doesn’t know what comes next.

What’s clear on both sides of the border is that the current situation serves no one. Not officials on the U.S. side working to secure the border, and not the families and children seeking legal protection by crossing it.

So the question they’re all looking towards Washington to answer is: What comes next?

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