SAN ANTONIO (AP) — At least nine people died after being crammed into a sweltering tractor-trailer found parked outside a Walmart in the midsummer Texas heat, authorities said Sunday in what they described as an immigrant-smuggling attempt gone wrong.

The driver was arrested, and nearly 20 others rescued from the rig were hospitalized in dire condition, many with extreme dehydration and heatstroke, officials said.

"We're looking at a human-trafficking crime," Police Chief William McManus said. He called it "a horrific tragedy."

Authorities were called to the San Antonio parking lot late Saturd...