SAN ANTONIO, Texas (KGO) -- Nine people are reportedly dead and at least 17 are in critical condition after a tractor trailer filled with undocumented immigrants was discovered at the border on a sweltering day.
Authorities in Texas are considering this an immigrant smuggling attempt gone wrong.
The gruesome discovery happened in a San Antonio Walmart parking lot.
The U.S. Attorney's Office says the driver of the truck has been identified and is in custody. A criminal complaint is expected to be filed as early as Monday morning.
Officials are calling it a deadly case of human smuggling. At least 39 people were inside the big rig truck.
"The air conditioning was not working so everyone was removed," an official said.
Thirty people are being treated at area hospitals and at least two of the victims are under 18 years old.
"We triaged each one of these people. This was a mass-casualty situation for us so we treat it as you do an airline crash or any kind of major incident," the official said. "We utilized helicopters to fly people out. We utilized at least seven hospitals."
Authorities found one person in a wooded area near the Walmart Sunday morning. It's believed many more people escaped the trailer before authorities arrived.
It wasn't until someone inside the trailer asked a Walmart employee for water that the employee then called police.
The U.S. Attorney's Office in the Western District of Texas says investigators have identified the driver as 60-year-old James Mathew Bradley Junior of Clearwater, Florida.
Bradley, who's in custody, and everyone else found to be involved is expected to face state and federal charges as early as Monday.
Officials say they will not release the identities of the victims or where they're from until their families can be notified.
Click here for more stories about immigration.
9 dead, 17 in critical after human-smuggling incident in Texas