The driver of the tractor trailer that was transporting undocumented immigrants, and had several dead bodies inside, is due to face criminal charges.
Texas authorities were called to a San Antonio Walmart lot, finding the trailer parked.
Inside they found eight dead bodies and 30 other undocumented immigrants severely injured from overheating inside.
ICE officials say a ninth person later died in the hospital and now another has died.
The driver, James Bradley Jr., was arrested and those who survived were hospitalized and classified as being in dire condition with many of them suffering from extreme dehydration and heatstroke.
ICE acting Director Thomas Homan says some of the survivors were interviewed and it was found that more than 100 people had been packed into the back of the 18-wheeler at one point.
Homan says it is unlikely the truck was used to carry immigrants across the border and that some of the survivors appeared to be between 10-17 years old.