Harlingen, Texas ? He’s the oldest of seven children from a dusty, destitute village in eastern Guatemala called Chiquimila, and the first in his family to learn how to read and write.

Edgar Lemus wanted the same opportunity for his younger siblings when he set out with his father for the United States to earn money to send them to school.

The two men were already 40 miles over the U.S. border, headed for a cousin’s home in New York, when the sugar cane field they and four other illegal immigrants were hiding in erupted in flames.

It’s unclear if they knew it was harvest time, when fields are intentionally burned.

“Maybe they were sleeping,” Willacy County Sheriff Larry Spence said. “Or maybe they heard the warnings and thought it was some kind of trick.”

Lemus, burned over 80 percent of his body, was the sole survivor. On Sunday, nearly a week later, the 20-year-old remained in critical condition at a Dallas hospital.

“I understand he was a tough guy, he is someone who perseveres, so I think he’s trying,” said Carmina Maldonado, of the Guatemalan consulate in Houston, who spoke with Lemus’ family.

“Please pray for this guy,” she added. “He’s fully alert, and he is suffering.”

The deaths of Lemus’ father and the others — one carrying Guatemalan documents and three from Mexico — are among dozens of immigrants each year trying to cross the border into the United States. Some advocates blame government crackdowns that force immigrants toward risky routes. Other migrants suffer because of unscrupulous guides. Most remain anonymous, buried in county graves.

“Oftentimes, the sense is this happens and no one ever knows it,” said Nathan Selzer of Proyecto Libertad, a Harlingen-based group that offers assistance to immigrants.

Roberto Martinez, former director of the Border Project of the American Friends Service Committee, a Quaker organization, said in the past nine years, more than 2,200 people have died crossing the border.

He and Selzer both blame initiatives to clamp down at border crossings, saying they only force migrants to take riskier routes.

“The question is, how many more must die before they realize the futility of it?” Martinez said.

Border Patrol spokesman Xavier Rios said agents had placed messages about the dangers of crossing the border on Latin American television and radio stations. Agents constantly rescue people from airless trunks and truck compartments, he said — an indication of the ruthlessness of paid guides.

In last Monday’s tragedy, farmers had arranged for the field burning to make it easier to cut the 10-foot stalks and bring them to the mill for processing. In the 1970s, it became a requirement to post notices before each burn, and to play a warning over a loudspeaker in both Spanish and English.

Martinez said it’s not hard to imagine what the six were doing in the isolated field.

“We have that happen a lot — hiding in fields waiting for the chance to make it to the main road,” he said. “Usually they hide during the day and move at night. They never carry enough water.”

Officials have not yet released the name of Lemus’ father. Maldonado said he was in his early 50s.

Another of the migrants carried papers identifying him as Lencho Calderon. “No one has claimed him yet,” Maldonado said. “But they say he’s not in his village.”

Carlos Martinez, spokesman for the Mexican consulate in Brownsville, said he was waiting for clearance from Mexico City before releasing the names of the three others. Both governments are working to get the bodies back home.

“You have an immigrant who dies. There’s no verification, there’s no closure,” Selzer said. “We certainly hope the families in these cases are identified and the victims are laid to rest.”