The victims were discovered during a routine inspection at a busy rail yard near the Mexican border.
LAREDO, Texas — Authorities in South Texas are investigating the deaths of six people whose bodies were found inside a freight train boxcar Sunday at a Union Pacific rail yard near the U.S.-Mexico border, where temperatures approached triple digits.
Investigators said the discovery happened during a routine inspection before the train was scheduled to continue north from Laredo. Emergency responders arriving at the rail yard found six people dead inside the enclosed railcar, according to local police. Officials have not released the identities of the victims and said investigators are still working to determine whether the deaths resulted from heat exposure, suffocation, dehydration or another cause. The case immediately drew attention because of previous incidents involving migrants traveling through South Texas in dangerous cargo compartments during periods of intense heat.
Police said a Union Pacific employee alerted authorities shortly before 3 p.m. after finding several unresponsive individuals inside the boxcar near Jim Young Way and Interstate 35. Firefighters, paramedics and police officers entered the rail yard while investigators blocked off nearby sections of track. Officers spent hours documenting evidence and examining the railcar’s locking mechanisms. Authorities later confirmed all six victims died before emergency crews arrived. Investigators said the railcar appeared to have been sealed during transit, though officials did not explain whether anyone had access to ventilation inside the container. “This remains a very active investigation,” police spokesperson Jose Espinoza said Sunday night. Detectives also interviewed railroad employees who handled the train before it arrived in Laredo.
Medical officials said the victims included five men and one woman, though formal identifications were still pending Monday afternoon. Webb County Medical Examiner Dr. Corinne Stern said preliminary findings suggested heat-related illness may have contributed to at least one death. Temperatures in Laredo climbed into the high 90s Sunday, creating severe conditions inside enclosed cargo containers made of metal. Investigators recovered personal documents, cellphones and backpacks from inside the railcar as they worked to identify the victims and trace their recent movements. Officials declined to confirm reports that some victims may have been migrants traveling through the border region. Authorities also have not said how long the individuals were inside the boxcar or where the train began its route before stopping in Laredo. Additional autopsies and toxicology testing are expected later this week.
The deaths underscored continuing concerns along the southern border, where freight trains and commercial vehicles are sometimes used in human smuggling operations. South Texas has experienced multiple deadly incidents involving migrants trapped in poorly ventilated vehicles during extreme weather conditions. In June 2022, dozens of migrants died inside a tractor-trailer abandoned near San Antonio after traveling without functioning air conditioning. Border authorities and humanitarian groups have also documented cases involving migrants hidden inside train cars, cargo trailers and shipping containers. Laredo remains one of the nation’s busiest trade corridors, handling major rail shipments crossing between the United States and Mexico every day. Officials said investigators are examining whether the victims entered the railcar in Mexico, in Texas or at another location farther south along the train route.
Federal and state agencies joined the investigation Monday as detectives worked to reconstruct the timeline leading to the deaths. Texas Rangers, Customs and Border Protection personnel and railroad investigators all responded to the rail yard. Police said investigators planned to review shipping records, surveillance video and communications logs connected to the train’s route. Union Pacific spokesperson Daryl Bjoraas said the railroad was cooperating fully with authorities and assisting investigators with operational information. Officials also planned to coordinate with foreign consulates if any victims are confirmed to be citizens of other countries. No arrests had been announced by Monday evening, and police said it was too early to determine whether criminal charges could follow. Authorities expect medical findings and additional interviews to shape the next phase of the investigation.
The discovery shook residents in Laredo, a border city where freight trains are a constant presence near industrial districts and neighborhoods. On Monday, police vehicles remained stationed near the rail yard entrance while workers moved slowly through adjacent sections of track. Some nearby residents said they first realized something was wrong after hearing sirens and seeing emergency crews gather Sunday afternoon. Mayor Victor Treviño described the deaths as heartbreaking and said the city would continue supporting investigators and emergency responders. Community groups that assist migrants along the border also expressed concern as authorities worked to identify the victims and notify relatives. Clergy members from several local churches said prayers were held Monday evening for the unidentified dead and their families.
Authorities said forensic examinations and identification efforts were continuing Monday night. Investigators expect to release additional information after autopsies are completed and officials confirm the victims’ identities and travel history.
Author note: Last updated May 11, 2026.