US authorities opened a criminal investigation on Tuesday into the deaths of at least 51 migrants, who had been left in a stifling lorry in Texas.
A representative for US Immigration and Customs Enforcement said the death toll had risen overnight after the abandoned tractor-trailer was discovered on Monday on an isolated road near the city of San Antonio.
Sixteen people, including four children, were taken to hospital suffering from extreme dehydration. US media reported that some victims had died in hospital.
US President Joe Biden said the grim incident underscored the need to shut down “the multibillion dollar criminal smuggling industry preying on migrants”.
“The tragic loss of life in San Antonio, Texas, that took place yesterday is horrifying and heartbreaking,” he said in a statement.
A city worker heard a cry for help from the lorry shortly before 6pm on Monday and discovered the gruesome scene, local police chief William McManus said.
Hours later, body bags lay spread on the ground near the lorry as authorities responded to the calamity.
San Antonio Mayor Ron Nirenberg said the migrants who died, most of whom were Mexican citizens, had “families who were likely trying to find a better life”.
“This is nothing short of a horrific human tragedy,” he said.
It was the deadliest single incident involving migrants along the southern border in recent history and has drawn more attention to the risks that hundreds of thousands of people face as they attempt to enter the US from Mexico illegally.
Ten migrants died in 2017 after being trapped inside a lorry parked at a Walmart shop in San Antonio. In 2003, the bodies of 19 migrants were found in a sweltering lorry south-east of San Antonio.
The home countries of the migrants and how long they were abandoned on the side of the road were 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 US.
Officers arrived to find a body on the ground outside the trailer and a partially opened gate.
Three people were taken into custody but it was unknown if they were definitively connected with human trafficking, Mr McManus said.
The 16 people taken to hospitals with heat-related illnesses were hot to the touch and dehydrated, and no water was found in the lorry, said fire chief Charles Hood said.
“They were suffering from heat stroke and exhaustion,” Mr Hood said. “It was a refrigerated tractor-trailer, but there was no visible working AC unit on that rig.”
Those in the lorry were part of a presumed migrant smuggling attempt into the US, and the investigation was being led by Homeland Security Investigations, Mr McManus said.
Lorries became a popular smuggling method in the early 1990s amid a surge in US border enforcement operations in San Diego, California, and El Paso, Texas, which were then the busiest corridors for illegal crossings.
Before that, people paid small fees to individual operators to transport them across a largely unguarded border. As crossing became exponentially more difficult after the 2001 terror attacks in the US, 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 on Monday, but temperatures approached 37ºC.
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Migrants — largely from Mexico, Guatemala, Honduras and El Salvador — have been expelled more than two million times under the Title 42 order, a coronavirus pandemic-era rule in effect since March 2020 that denies them a chance to seek asylum but encourages repeat attempts because there are no legal consequences for those that are caught.
People from other countries, notably Cuba, Nicaragua and Colombia, are subject to Title 42 less frequently due to the higher costs of sending them home, strained diplomatic relations and other considerations.
Customs and Border Protection reported 557 deaths on the south-west border in the 12-month period ending September 30, more than double the 247 deaths reported in the previous year and the highest since it began keeping track in 1998. Most are related to heat exposure.
CBP has not published a death tally for this year but said that the patrol had performed 14,278 “search-and-rescue missions” in a seven-month period through May, exceeding the 12,833 missions performed during the previous 12-month period and up from 5,071 the year before.
Agencies contributed to this report
