SAN ANTONIO, Texas — The tractor-trailer was pitch-black inside, crammed with maybe 90 immigrants or more, and already hot when it left the Texas border town of Laredo for the 150-mile trip north to San Antonio.

It wasn’t long before the passengers, sweating profusely in the rising oven-like heat, started crying and pleading for water. Children whimpered. People took turns breathing through a single hole in the wall. They pounded on the sides of the truck and yelled to try to get the driver’s attention. Then they began passing out.

By the time police showed up at a Walmart in San Antonio around 12:30 a.m. on Sunday and looked in the back of the truck, eight passengers were dead and two more would soon die in an immigrant-smuggling attempt gone tragically awry.

The details of the journey were recounted on Monday by a survivor who spoke to The Associated Press and in a federal criminal complaint against the driver, James Matthew Bradley, who could face the death penalty over the 10 lives lost.

“After an hour I heard... people crying and asking for water. I, too, was sweating and people were despairing. That’s when I lost consciousness,” Adan Lara Vega, 27, told the AP from his hospital bed. By the time he came to, he was in the hospital, where his ID bracelet identified him by the last name Lalravega. Mexican consulate and US officials later told AP the correct spelling was Lara Vega.

Bradley, 60, of Clearwater, Florida, appeared in federal court on charges of illegally transporting immigrants for financial gain, resulting in death. He was ordered held for another hearing on Thursday.

He did not enter a plea or say anything about what happened. But in court papers, he told authorities he didn’t realize anyone was inside his 18-wheeler until he parked and got out to relieve himself.

In addition to the dead, nearly 20 others rescued from the rig were hospitalized in dire condition, many suffering from extreme dehydration and heatstroke.

Mexico’s foreign ministry released a statement on Monday night that said “according to preliminary information,” 25 of the migrants inside the rig were Mexican.

Four of those who died and 21 of those hospitalized are Mexican, the statement said. Some of the others inside the truck were from Guatemala.

Many of the immigrants had hired smugglers who brought them across the US border, hid them in safe houses and then put them aboard the tractor-trailer for the ride northward, according to accounts given to investigators.

“Even though they have the driver in custody, I can guarantee you there’s going to be many more people we’re looking for to prosecute,” said Thomas Homan, acting director of US Immigration and Customs Enforcement.

Bradley told investigators that the trailer had been sold and he was transporting it for his boss from Iowa to Brownsville, Texas. After hearing banging and shaking, he opened the door and was “surprised when he was run over by ‘Spanish’ people and knocked to the ground,” according to the criminal complaint. — AP