One migrant who was removed from the tractor-trailer in which eight others were found dead has died in a San Antonio, Texas, hospital, Immigration and Customs Enforcement (ICE) confirmed to EFE on Sunday.

ICE provided no further details about the tragedy, for which the agency and local politicians have blamed people smugglers. 

San Antonio is a few hours' drive from the border with Mexico, and the US immigration department is trying to establish the victims' legal status.

According to the New Yorker, which recently published an in-depth story about Texas, one of Texas Governor Greg Abbott’s priorities essentially required Texas officials to join the Trump Administration’s crackdown on undocumented immigrants. There are about a million of undocumented immigrants in Dallas and Houston alone. 

In May, Gov. Abbott signed Senate Bill 4, a piece of legislation that penalized 'sanctuary cities". Basically, SB4 penalizes sheriffs, constables, police chiefs, and other local leaders who don’t cooperate with federal immigration authorities or prevent rank-and-file officers from asking about immigration status. Immigrants rights’ activists are concerned the law will lead to racial profiling, and law enforcement officials worry that the law will force them to prioritize immigration violations over other, more serious crimes, as reported in The Atlantic. 

Earlier reports were that eight migrants were found dead and 20 injured on Sunday inside a parked tractor-trailer in central Texas, in what police have termed a human trafficking case.

The vehicle was found in a Walmart parking lot in the city of San Antonio after an employee at the discount hypermarket alerted police late on Saturday night.

When officers arrived at the scene, they found a total of 38 people inside the trailer, including eight corpses at the back, said San Antonio Police Chief William McManus at a news conference.

All of the vehicle's occupants were between 20-30 years old, McManus added.

San Antonio Mayor Ron Nirenberg told the BBC that caring for the victims was the authorities' first aim. "Our most important focus right now is to deliver compassionate care," he said.

Acting ICE director Thomas Homan on Sunday called the situation a "horrific tragedy" which he blamed on people traffickers who, he said, do not care about the lives of those whom they transport.

Emergency services extricated 20 people who were immediately hospitalized, some in critical condition, according to the city's fire chief, Charles Hood.

Hood added that the trailer's air conditioning system was not working, which probably caused the victims to die of heat stroke or dehydration.

  Temperatures in central Texas in July reach, on average, a daily maximum of between 33-37 C (92-98 F).