From Del Rio to Laredo: The journey of seven migrants who suffocated on a Union Pacific train in Texas

From a Union Pacific train, a migrant woman texted a relative on Saturday. The railway car she was in felt very hot, she wrote. That day, the temperature in San Antonio, Texas, where the train was traveling, reached nearly 90 degrees Fahrenheit (32 degrees Celsius). Authorities estimate that the heat index inside the shipping containers could have reached as high as 140 degrees Fahrenheit (60 degrees Celsius). San Antonio police were alerted to the woman’s text messages, but they were unable to locate the train.

On Sunday afternoon, more than 100 miles (160 km) away in Laredo, Texas, a Union Pacific employee found six people dead inside a railcar, a spokesperson for Immigration and Customs Enforcement (ICE) told EL PAÍS. Homeland Security Investigations (HSI) officers responded after being notified by the police department of this border city.

Webb County Medical Examiner Corinne Stern and her team are examining the bodies. As of Tuesday, they had only been able to identify five people. They are two Honduran immigrants, one 14 years old and the other 24; and three Mexicans, ages 29, 45, and 56. Among them is a woman whom police believe is the same person who sent the text messages.

Forensic evaluations of this woman have determined that she died from hyperthermia, a body temperature elevated above tolerable levels. “While formal evaluations of the other five bodies are still pending, it is quite likely that hyperthermia was the cause of death for the entire group,” Stern explained in a county statement. The coroner told the Associated Press that she estimates the migrants suffered for nearly eight hours before dying.

With the discovery of the first six bodies, the investigation began to yield new information about what happened inside the railcar. It led to another body.

The doors opened from the outside

On Monday afternoon, Bexar County Sheriff Javier Salazar presented a timeline at a press conference in San Antonio, standing beside the tracks where the Union Pacific train had passed over the weekend. His location was not accidental.

At 1:30 p.m., just a few feet away, Union Pacific workers found a seventh body beside the tracks. This migrant’s documents indicated he was a resident of Mexico. Salazar said that the police involved and federal agencies believed the individual had been on the same train as the other six deceased individuals.

“He was part of the group that was being trafficked into the country in one of these containers. And for some reason, at some point, when the sensor (on the door) turned off here, he could have been thrown from the train after dying, or he could have fallen from the train and died as a result.”

This migrant is not yet included in the Webb County Medical Examiner’s Office case summary.

According to Salazar, the sensor on the train car activated to open the door twice during the journey: first in Del Rio, also on the border with Mexico, where it is believed the migrants boarded the freight train, and then in San Antonio. At the latter location, he said they don’t know if it was opened to allow more people to escape alive or simply to throw out the body.

“Those cars can’t be opened from the inside. (...) We think it was a coyote who opened the door from the outside,” he explained. The ICE spokesperson told EL PAÍS that the case is being investigated by HSI, the Laredo Police Department, and the Texas Rangers as a potential human trafficking incident.

EL PAÍS contacted Union Pacific regarding the incident. They did not respond to inquiries but issued a statement assuring authorities they are cooperating with the investigation. Further information was also requested from the coroner’s office, but no response was received by the time of publication.

A deadly stretch

The stretch between Laredo and San Antonio is frequently used by smugglers to move migrants from Texas, a state bordering Mexico, to various cities within the state and even across the country. It is the starting point for numerous internal migrant journeys each year.

In the last decade, news reports have been filled with incidents and deaths of migrants at this border crossing. The worst occurred in 2022, in a human trafficking case considered by authorities to be the deadliest in U.S. history.

More than 50 migrants from Guatemala, Honduras, and Mexico died of asphyxiation while being transported inside a trailer without air conditioning or water on a June day when temperatures reached nearly 104 degrees Fahrenheit (40 degrees Celsius). They were transported in those conditions for about three hours, from Laredo to San Antonio. By the time the trailer was opened, most had already died; another group died en route to the hospital. There were children and a pregnant woman among them.

In general, migration to the United States by train, truck, or on foot across the southern border remains risky, not only because of the extreme terrain conditions—the sweltering heat and aridity of the road—but also because of the dangers and violence they face when they fall into the hands of human traffickers.

The International Organization for Migration (IOM) reported in April that at least 414 migrants died or went missing in the Americas during 2025. This number is lower than the previous year, partly due to reduced migration flows resulting from President Donald Trump’s hardline policies—which ended access to asylum at the border.

Despite this, approximately 41% of the total deaths occurred on the US-Mexico border (131). Most were due to drowning while attempting to cross the strong currents of the Rio Grande, but others were caused by the extreme conditions they endured (limited access to water or food) while being transported by smugglers.

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