SAN ANTONIO, Texas-- Investigators say 9 people are dead and dozens more are in the hospital, after they were found inside a semi-trailer with an Iowa license plate.
It's registered to Pyle Transportation Incorporated, a company out of western Iowa.
The trailer was parked in a Walmart lot in San Antonio Sunday night. Investigators say a store employee called police, after someone from the truck asked him for water.
Police found 38 people inside the semi. Eight of them were dead; the others were taken to the hospital, where a ninth person died.
Those still alive are expected to have incurred brain damage from the severe heat.
Investigators say the high temperature in San Antonio was 100 degrees yesterday, and the trailer's air conditioner wasn't working.
The U.S. Attorney's office is holding 60-year-old James Bradley, Jr. of Clearwater, Florida in connection with the case, which they're calling a "horrific" human trafficking crime.
San Antonio Fire Department Chief Charles Hood described arriving on the scene, recalling, "Our paramedics and firefighters found that each one of them had heart rates over about 130 beats per minute, which, again, they were very hot to the touch. So, these people were in that trailer without any signs of any type of water. You're looking at a lot of heatstroke, a lot of dehydration."
Police are reviewing store surveillance footage, and have also searched the area with helicopter after some people reportedly ran off into the woods or were picked up by other drivers.
The driver of the tractor-trailer, Bradley, Jr., was arrested and will face state and federal charges.