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.Thirty-nine were inside when rescuers arrived, and the rest were believed to have escaped or hitched rides to their next destination, officials said. Some of the survivors told authorities they were from Mexico, Homan said.[SNIP]...investigators were still gathering evidence from the tractor-trailer, which had an Iowa license plate and was registered to Pyle Transportation Inc. of Schaller, Iowa.