LAREDO, Texas (AP/NBC)— Six people were found dead inside a sealed cargo boxcar at a Union Pacific rail yard in Laredo, Texas, on Sunday afternoon, baked to death in temperatures that climbed to 105 degrees in one of the deadliest suspected human smuggling discoveries along the Texas-Mexico border in recent memory.
A Union Pacific employee found the bodies around 3 p.m. and called police. Officers arrived to find five men and one woman dead inside the shipping container. One of the male victims appeared to be a teenager. None had made it out.
Webb County Medical Examiner Dr. Corinne Stern completed an autopsy on the female victim — a 29-year-old Mexican national — and ruled her death accidental, caused by hyperthermia. Heat stroke killed her. Stern said she believes the same cause will apply to all six once the remaining autopsies are finished.
“I’ve ruled that an accidental death,” Stern said, adding her belief that the others died the same way.
She estimates the group died within eight hours of being sealed inside. “Based on my examination on the scene and what I know of from the investigation, I really believe they were dead in less than eight hours,” Stern said.
The Webb County Medical Examiner’s Office identified a second victim Monday — a 24-year-old man from Honduras. Identification cards and cellphones recovered from the scene suggested the group originated from Mexico and Honduras. Fingerprints were taken and shared with U.S. Border Patrol through the Missing Alien Agency program to confirm identities. All six victims’ phones were turned over to investigators for data extraction. The Mexican consulate was contacted after the woman was identified.
Homeland Security Investigations confirmed it is treating the case as a potential human smuggling operation. “HSI is actively investigating this case as a potential human smuggling event with assistance from the Laredo Police Department and Texas Rangers,” the agency said in a statement.
Inside the Investigation
The train’s origin was not immediately established, and investigators said that question sat at the center of the ongoing inquiry. Jose Baeza, public information officer for the Laredo Police Department, described the rail yard’s scale to put the challenge in context.
“Imagine a loading dock at a seaport, but for trains,” Baeza said. “This is where they load and unload a lot of rail cars.”
The travel history of the specific shipping container had not been determined. Investigators also had not established why the six people inside did not attempt to exit the container as conditions deteriorated — a question that may point to the container being locked from the outside, a common method used by smugglers to prevent detection during transit.
Union Pacific said in a statement it was “saddened by this incident” and was cooperating fully with law enforcement. The company has operated inspection portals at border crossings for years that scan trains and photograph their contents to detect contraband and unauthorized passengers. How six people passed through that system undetected remained an open question Sunday night.
Laredo sits on one of the busiest trade corridors in North America. As of 2024, Port Laredo handled 62 percent of Texas’s land port trade, valued at nearly $340 billion, according to the Texas Comptroller of Public Accounts. The same infrastructure that moves hundreds of billions of dollars in commercial goods also creates the chokepoints and slow zones that smuggling networks have exploited for decades.
Stern did not soften the broader picture. “This was a horrific scene,” she said, before noting that migrant deaths are a routine reality in the 10-county region her office covers. “This spring has been busier than it was this time last year,” she added — a statement that carries its own weight given what last year looked like.
The Smuggling Network Behind the Deaths
Sunday’s discovery did not occur in isolation. It sits within a long and bloody history of human smuggling operations that treat human beings as cargo — sealed in containers, packed into trucks, hidden in rail cars — and abandon them when things go wrong.
In 2022, 53 migrants were found dead in the back of a sweltering tractor-trailer in Texas in what remains the deadliest human smuggling incident in American history. Two smugglers were subsequently sentenced to life in prison for their roles in those deaths.
A parallel case out of a 2021 crash in Mexico showed how these networks operate across borders and jurisdictions. At least 160 migrants, many from Guatemala, were packed into a semitrailer truck that struck the support base of a pedestrian bridge in Chiapas state on Dec. 9, 2021, and overturned. At least 53 people were killed. More than 100 were injured. Video from the scene showed bodies and survivors tangled inside the collapsed freight container, including unaccompanied children.
Daniel Zavala Ramos, 42, a Guatemalan national, pleaded guilty in federal court in Laredo to conspiring to smuggle migrants from Guatemala through Mexico to the United States in a scheme that placed lives in jeopardy and caused serious injuries and deaths. He faces a possible life sentence. Sentencing is set for July 7. Five co-defendants remain in pretrial proceedings.
Prosecutors described a smuggling operation that moved migrants on foot, inside minibuses, cattle trucks, and tractor trailers, using Facebook Messenger to coordinate document transfers and provide scripts to unaccompanied children on what to say if they were caught.
Ramos was extradited from Guatemala in 2025 after his arrest on the third anniversary of the crash in 2024.
Smuggling on trains crossing into the United States has been a persistent concern for decades. Trains heading north from Mexico frequently slow or stop before crossing the border, creating windows for smugglers and migrants to board or conceal themselves and their cargo. Union Pacific has invested in scanning technology specifically to address the problem, but Sunday’s deaths suggest the measures have limits.
Border encounters along the southern border dropped significantly toward the end of the Biden administration and have reached record lows under Trump’s second term. In Laredo’s sector, Border Patrol agents were encountering approximately 40 people per day crossing illegally in March — making it the third busiest of nine sectors along the border. Fewer legal crossings have not eliminated the smuggling networks. They have changed their methods.
The six people who died Sunday in that boxcar in Laredo were not statistics when they climbed into that container. They were people who made a calculation — that the risk of the journey was worth whatever waited on the other side. The smugglers who put them there made a different calculation: that the profit was worth the risk to themselves, not the risk to their cargo.
That asymmetry is the defining feature of human smuggling economics. The smugglers collect payment upfront. The migrants bear all the physical risk. When a container gets too hot or a truck overturns, the smugglers are typically miles away, and the people they were paid to move are the ones who die.
The legal consequences, when they come, are severe — life sentences in the 2022 Texas truck case, potential life imprisonment for Zavala Ramos in the 2021 Chiapas crash. But enforcement after the fact does not reach the six people who died in Laredo on a Sunday afternoon when the temperature hit 105 degrees and nobody came to open the door.
Dr. Stern’s observation that this spring has been busier than last year for migrant deaths in her region suggests that record-low border encounter numbers have not translated into fewer people attempting the crossing. They may simply be attempting it in more dangerous ways, through more dangerous intermediaries, in containers that are harder to detect and harder to escape.
The rail yard in Laredo will process thousands more containers this week. The scanning portals will take their photographs. And somewhere in the network that put six people in that boxcar, someone is already calculating the next shipment.
