At least 46 people found dead in Texas trailer truck

Forty-six people were found dead and 16 others were taken to hospital after being found inside a tractor-trailer rig on Monday on a remote back road in south-west San Antonio , Texas officials have said. The discovery may prove to be the deadliest tragedy among thousands who have died attempting to cross the US border from Mexico in recent decades. A city worker at the scene was alerted by a cry for help shortly before 6pm Monday, police chief William McManus said.

Officers arrived to find a body on the ground outside the trailer and a partially opened gate to the trailer, he said. Sixteen were taken to hospital with heat-related illnesses, of which 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.

Mexico’s foreign minister said two people from Guatemala were among those sent to hospital. Relaying information from the Mexican consul in San Antonio, Marcelo Ebrard said the survivors had been taken to four hospitals around the city. Three people were taken into custody, but it was unclear if they were connected to human trafficking, McManus said.

Those in the trailer were part of a presumed smuggling attempt for those attempting to enter the United States, and the investigation was being led by US Homeland Security Investigations, McManus said. Secretary of Homeland Security Alejandro Mayorkas said on Twitter he was “heartbroken by the tragic loss of life” in San Antonio. He also confirmed US Immigration and Customs Enforcement (ICE) have launched a federal investigation into the deaths, with support of local police and the border force.

Ebrard said the Mexican consul was en route to the site on Monday. The Mexican general consulate in San Antonio said on Twitter that it would provide aid to any Mexicans involved in the incident. It also said consul general Ruben Minutti was on his way to the scene.

Governor Greg Abbott said in a tweet the people were found in the back of a truck and blamed the deaths on political division and how borders are secured. The mayor of San Antonio, Ron Nirenberg, said the 46 who died had “families who were likely trying to find a better life”. “This is nothing short of a horrific human tragedy,” Nirenberg said.

The city has been the scene of previous migrant deaths. Ten people died in 2017 after being trapped inside a truck that was parked at a Walmart in San Antonio. In 2003, 19 others were found in a sweltering truck south-east of San Antonio.

Map of San Antonio v2 Big rigs emerged as a popular smuggling method in the early 1990s amid a surge in US 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 US, individuals were led through more dangerous terrain and paid thousands of dollars more.

Law enforcement officers work at the scene where people were found dead inside a trailer truck in San Antonio, Texas Photograph: Kaylee Greenlee Beal/Reuters Heat poses a serious danger, because temperatures can rise steeply inside vehicles. Weather in the San Antonio area was mostly cloudy Monday, but temperatures approached 100F (38C). Photos posted to Twitter by a KSAT reporter showed multiple police vehicles and ambulances surrounding a large truck.

Associated Press and Reuters contributed to this story. .