Six people were found dead Sunday afternoon inside a Union Pacific boxcar at a rail yard in Laredo, Texas, police confirmed. An employee loading the train car discovered the bodies around 3 p.m. local time and reported the finding to authorities. Police and fire departments responded to the scene, though the circumstances of their deaths remain under investigation. Investigators have not yet identified the victims.

Laredo sits on the U.S.-Mexico border approximately 160 miles southwest of San Antonio. Temperatures in the city exceeded 90 degrees on Sunday. Union Pacific stated it is working closely with law enforcement to investigate. "We are deeply saddened by this incident," said Daryl Bjoraas, a company spokesman. Officials could not confirm whether the deceased were migrants attempting to cross into the United States.

The discovery echoes previous deadly incidents along the border. In 2022, 53 migrants—47 adults and six children—were found in a tractor-trailer outside San Antonio in one of the nation's deadliest human smuggling cases. A year later, two migrants died and five others were critically injured inside a shipping container on a train in Uvalde County. Migrants often ride in such containers without realizing temperatures can become lethal.