It’s among the deadliest of the tragedies that have claimed thousands of lives in recent decades as people attempt to cross the U.S. border from Mexico. Ten migrants died in 2017 after being trapped inside a truck parked at a Walmart in San Antonio. In 2003, the bodies of 19 migrants were found in a sweltering truck southeast of San Antonio.
The home countries of the immigrants and how long they were abandoned on the side of the road was not immediately known.
South Texas has long been the busiest area for illegal border crossings. Migrants ride in vehicles through Border Patrol checkpoints to San Antonio, the closest major city, from which point they disperse across the United States.
Officers arrived to find a body on the ground outside the trailer and a partially opened gate to the trailer. Three people were taken into custody, but it was unclear if they were definitively connected with human trafficking, McManus said.
Of the 16 taken to hospitals with heat-related illnesses, 12 were adults and four were children, said Fire Chief Charles Hood. The patients were hot to the touch and dehydrated, and no water was found in the trailer, he said.
“They were suffering from heat stroke and exhaustion,” Hood said. “It was a refrigerated tractor-trailer, but there was no visible working AC unit on that rig.”
Those in the trailer were part of a presumed migrant smuggling attempt into the United States, and the investigation was being led by U.S. Homeland Security Investigations, McManus said.
Big rigs emerged as a popular smuggling method in the early 1990s amid a surge in U.S. border enforcement in San Diego and El Paso, Texas, which were then the busiest corridors for illegal crossings.
Before that, people paid small fees to mom-and-pop operators to get them across a largely unguarded border. As crossing became exponentially more difficult after the 2001 terror attacks in the U.S., migrants were led through more perilous terrain and paid thousands of dollars more.
Heat poses a serious danger, particularly when temperatures can rise severely inside vehicles. Weather in the San Antonio area was mostly cloudy Monday, but temperatures approached 100 degrees.