Crossing illegally from Central America through Mexico into the US is terribly dangerous, in many ways. Yet, more than 50,000 underage migrants have been caught trying to cross the US southern border in the last year.

Some jump a freight train known as "The Beast," where one false step could mean a lost limb — or worse. Some are kidnapped by drug cartels, others by freelance criminals and held for ransom. So why would any parent send their children on the journey, alone?

For many, like Jose and Ester, the answer is fear and desperation. They are undocumented immigrants from El Salvador, living in the suburbs of Baltimore. And they asked that their last name be withheld to protect their identity. They have two boys — ages 11 and 9.

Like many others, they left their kids behind to find work in the US. Jose said when his youngest son — his namesake, Jose Jr. — was born, he took one look at the baby and wondered how in the world he was going to feed his family.

“The truth is, everything I earned in the whole day wasn’t enough to buy tomatoes, potatoes ... the ingredients [for a family meal,]” Jose said.

In El Salvador, minimum wage can be as low as $4 a day, and living costs are high. “If you want to buy a chicken, you’ll pay $6,” he said.

Jose considered the $50 a week he made in El Salvador and the $500 he could earn in the US ... and packed his backpack. Ester stayed behind in El Salvador to raise the boys. Jose landed in Baltimore, where he now works cleaning apartment buildings. He earns $9 an hour, eight to 12 hours a day.

Piling trash bags night after night, Jose saved enough money to first bring his wife north. That was nearly two years ago. Ester and Jose had been apart for seven years at that point. They hoped to bring the boys along when they had earned enough.

“They’ve been strong,”Ester said, referring to her boys. She calls them “my little bugs.” But she has been very worried about them.

“It’s not the same to say, ‘Son, I love you,’ from far away,” Ester said.

In the last two years, El Salvador has become increasingly dangerous, especially the neighborhood where the boys live, near the northern town of Sonsonate.

“Sometimes, they have to take off running for the house because you can be caught in a gunfight there,” Jose said.

Stray bullets have hit neighbors. Gang members saunter into the boys’ elementary school in the middle of the day. It’s risky just sending them gifts from the US.

Jose said even an old-school pair of Nikes is off limits; the gangs go after anyone who wears them.

“You have to be especially careful when you buy shoes,” Jose said. “You can’t buy just any shoes because you can lose your life for them.”

The boys had some refuge at home, but that wasn’t entirely safe, either. Ester and Jose had left the boys with an aunt, who they thought would protect them. But she and other relatives turned on the boys, beat them with belts, yelled insults at them and then abandoned them. Finally, they were passed off to a 22-year-old cousin who has two children of her own.

“We are to blame for leaving them alone and not realizing they would suffer so many things,” Ester said.

When the couple first learned their kids were in danger, they started working longer days and saving more money. They finally made enough to pay for the kids' journey north.

“We’re spending almost $10,000,” Jose said.

Jose negotiated the route with a coyote, a human smuggler. There would be no death train; the boys would take cars and buses the whole way, and stay in hotels. The $10,000 pays for three attempts to get the boys across the US border.

“If you don’t make it in three tries, you lose the money,” Jose said.

In early May, the boys left on their first try.

“There are many dangers in the journey,” Jose said. “It’s incredibly dangerous to cross the border right now.”

Rafts along a river between Guatemala and Mexico. Migrants from Central America often cross into Mexico near Tapachula. Kevin, 11, and his brother José Jr., 9, crossed using an inflatable raft this summer and are now reunited with their parents in Maryland. Credit: Eric Lemus

Just an hour after crossing into Mexico, Jose said, the boys were caught. For three weeks, they were detained in Mexico in a high-security facility that houses mostly adult migrants. There, they had to wash their own clothes and barely had enough to eat.

Then, they were flown back to El Salvador, where they went to live with their cousin again. For the boys, their main lifeline to their parents was a shaky Internet connection. To them, Jose was a Facebook dad.

“The first time [we] bought a computer, I saw him on it,” Jose Jr. said. The father and his 9-year-old namesake are the spitting image of each other.

“He’s really chubby — just like me,” Jose Jr. added.

The boys barely left their cousin’s house in El Salvador because of the gangs. They played soccer, but indoors. They could have used the lawn, but it was full of trash. There was nothing to keep them here, and yet the 11-year-old, Kevin, said thinking about a second journey north was tough.

“My brother said he didn’t want to go,” Kevin said. Still, he told his parents that he was willing to give it another try.

In June, the boys set off for the second time. Barely a week into the journey, Jose and Ester received a phone call. It was from another family traveling in the same group as the boys. They were all being held hostage in their hotel rooms by men in Mexican police uniforms. The men were demanding money.

Desperate, Jose and Ester tried to call the coyote, but they couldn’t get through.

“You have reached a non-working number,” came the recorded reply. “Please check the number and dial again.”

They tried calling back; they tried different numbers. Every time, the same response: “You have reached a non-working number.”

It was painfully tense. “We just have to wait,” Jose told Ester. “We just have to wait.”

After two days of waiting, Jose finally got a call: The coyotes had paid the ransom. “They paid $1,000 for each of the boys so they would let them continue,” Jose said.

A few days and an all-night bus ride later, the boys arrived at the US border — just south of McAllen, Texas. Jose got a call from the coyotes saying they would try to cross that night.

Then, again, he heard nothing.

“So I begged God that we’d get news of the boys,” he said.

And at the same time, he prayed they wouldn’t show up as a statistic on the nightly news. Every year, hundreds of migrants heading north die in the desert or wash up on the banks of the Rio Grande. Jose said while they waited for word, his wife Ester became frantic.

“She got really stressed out,” he said. “I had to give her medicine to calm her down.”

During that time, Jose reached out to advocacy groups and government offices. “I was calling around to a bunch of organizations to see if they could find the boys or find out what happened,” he said.

After three days, he got a call from US immigration officials telling him that they had his sons — in detention in Texas. The boys were transferred several times. Finally, a week later, Jose got through to an office set up to unite kids like his with family in the US.

“We got news the boys were in a shelter for kids in Miami,” Jose said.

Under current US policy, unaccompanied minors from Central America, like Jose’s sons, are treated as possible trafficking victims. Most are given notices to appear at immigration court; the hearings sometimes happen within a few weeks. Many children who do appear arrive without a lawyer. While they wait for their hearings, kids are often reunited with relatives in the US.

In mid-July, Kevin and Jose Jr. were put on a plane from Miami. Ester and Jose showed up at the airport in Baltimore. They brought no toys, no candy, not even balloons — they were so afraid the boys wouldn’t appear.

“I was really anxious,” Jose said. “Would they come? Would there be bad news? Would they not be able to make it?”

Jose and Ester waited for 40 minutes at the arrivals area, until finally, Kevin and Jose Jr. walked around the corner. Years had passed since Jose and Ester had seen their boys in the flesh.

“It was a really emotional moment,” Jose said. “There was a lot of joy, but also a little bit of pain for all that they had gone through and suffered to be with us.”

José and Ester sent for their two sons, 11-year-old Kevin and 9-year-old José Jr. They were detained in Texas and transferred to a few centers along the southwest before they were sent to a shelter for unaccompanied minors in Miami and then reunited with their parents in Maryland. Their faces aren't shown to protect their identity. Credit: Courtesy of José and Ester

When they reunited, the parents finally got to hear how the boys crossed the Rio Grande — in an inflatable raft in the early morning hours.

“We were walking a long way, and you could see water — like lakes,” Jose Jr. said. “And we went and ...”

“There was a tunnel,” Kevin said, finishing his brother’s sentence.

“And then there was the street,” Jose Jr. said, continuing the story. “We went for the street and the police came.”

Jose Sr. said the boys still have bad dreams about the crossing and about being held hostage. “The little guy, Jose Jr., he’s still really anxious.”

But Jose Jr. said he’s happy to be in Maryland, “because now I’m with my dad and my mom.”

His dad is trying to find a way so they can stay. He plans to hire a lawyer to represent them at their hearing.

According to the Transactional Records Access Clearinghouse, a project at Syracuse University that tracks immigration cases, around 50 percent of undocumented kids with attorneys are allowed to stay in the US. That number drops to 10 percent for those who don’t have a lawyer.

Ester's dream is that the legal system will be kind to them. “I am just hoping we can stay together like a family,” she said.

For now, they’re enjoying the time they do have together. Ester has been making everyone’s favorite foods. “Today, it’s going to be chicken,” Jose Sr. said.

Ester is seven months pregnant now with the newest member of the family. And Jose Jr. recently celebrated his birthday with all the trimmings. “Cake, piñata, pizza, chicken,” Jose Jr. yelled out.

For Jose Sr., his sons’ happiness is proof that he and Ester made the right choice to bring them to the US — out of poverty and out of danger back home. Now they can provide for them and care for them.

“No one takes better care of kids than their parents,” he said.

Jose knows it’s still possible the boys will be deported, and that he and his wife are vulnerable, as well. But despite everything they’ve been through, and everything they’ve put their kids through, Jose said it’s worth it.

“If you were in my shoes,” he said, “what would you do to be together?”

This story was produced in association with Round Earth Media, mentoring the next generation of global journalists. Julia Botero, Eric Lemus and Manuel Ureste contributed to this reporting.