The seven children had just crossed the river, shoes still caked with mud, when U.S. Border Patrol agents stopped them.
The youngest was 6, Jon Smith Figueroa Acosta, he said, and he'd made the 2,000-mile journey from Honduras. He did not know to what city or state he was headed, but he had a phone number for his father in the United States.
"Estoy solo," he said, meaning, "I'm alone."
It was unclear how long the group had been traveling together, or who had brought them across the Rio Grande. There were two teenage siblings whose mother had sent for them after their elderly grandmother in Honduras could no longer care for them, and two teenage Nicaraguans.
Luis Arias Dubon, 15, said the trip required that he walk through much of Mexico for nearly a month.
He left San Pedro Sula, Honduras, when he was threatened by members of the deadly 18th Street gang.
"They tried to force me into the gang," he said, adding that he was afraid they'd kill him.
The recent spike in the number of unaccompanied minors crossing the border brought U.S. Customs and Border Protection Commissioner R. Gil Kerlikowske to the Rio Grande Valley sector this month.
"Historically the numbers would not be at the levels we see right now," Kerlikowske said, while standing in a warehouse where about 20 migrant children rested on large green mattresses, wrapped in reflective plastic blankets. "The concerning part is, are we seeing the new normal?"
A total of 10,588 unaccompanied children crossed the U.S.-Mexico border in October and November, more than double the 5,129 who crossed during the same two months in 2014, federal statistics show. The number of family members crossing together, meanwhile, has nearly tripled, to 12,505. And though the influx began in July, the numbers were slightly higher this fall, a time when colder weather usually drives down the number of migrants crossing.
Kerlikowske said his agency was better prepared to handle the influx than in summer 2014, when tens of thousands of unaccompanied children and families poured over the border, taxing agents and holding areas.
Recently, two camps in North Texas have opened as shelters, housing 900 unaccompanied child migrants from countries that don't border the U.S., who under federal law must be handed over to the Department of Health and Human Services within three days of being detained. A third facility is on the way, which will hold another 200. The children are being sent north to prevent a backlog at the border, health officials said.
The child migrants must be cared for until they can be united with a relative or sponsor, where they remain until immigration courts can decide on their cases.
In McAllen, a respite center run by Catholic Charities looks after families who have been released by Border Patrol and given notices to appear at U.S. Immigration and Customs Enforcement offices and immigration courts. Recently, mothers with children described various reasons for leaving: fleeing gang or domestic violence, providing opportunities to study for their children, reuniting with family who had long lived in the United States.
Ester Franco, 38, of El Salvador, said she left with her two teenage daughters, Yesica and Isela, out of fear for them because they are of the age when local gang members start to accost young girls. She had already pulled them out of school and still didn't feel safe, so she decided to bring them to Maryland, where her husband lives.
"What I want is security for my girls," she said. "I want them to be able to study."
On the other side of the border in Reynosa, Mexico, migrant shelters -- where people await their opportunity to cross -- were mostly empty. Maria Nidelvia Avila, the director of the Casa del Migrante, said children who travel without a parent don't stay in shelters. Instead, they go to bus terminals, then to stash houses around the outskirts of the city.
The journey through Mexico can be dangerous, as Marleny Gonzalez, who was staying at a nearby shelter in Mexico with her daughter, could attest.
The 24-year-old Guatemalan was in the bed of a pickup truck with other Central American migrants when it overturned near San Fernando, two hours south of Reynosa. Gonzalez wasn't hurt, but her 4-year-old's legs were broken. The child was in a cast covering her entire bottom half of her body, unable to sit up.
"Almost all my family is in the United States," Gonzalez, said, including her daughter's father. "I felt alone. My girl didn't have a father, so I wanted to travel."
Given her daughter's precarious state, she wasn't sure now whether she would make the rest of the trip.