Local authorities in San Antonio, Texas, have confirmed that eight people have been found dead inside a trailer.
The vehicle was parked in a Walmart car park. It is understood that a man got out of the truck and entered the Walmart store to ask for water. An employee provided the water and then called 911 to run a welfare check.
When police arrived, they searched the truck and found eight dead people inside and thirty others with severe heat-induce injuries.
The air conditioning inside the truck was not working, while temperatures outside reached almost 40C.
Police said that they were lucky to have found the truck when they did, as nobody would have survived inside in another few hours.
The truck driver was arrested, and police are looking for other suspects in relation to the grim discovery.