Death is a constant risk for undocumented migrants entering Texas

More than four dozen migrants were found dead in an overheated tractor-trailer on an industrial road in south San Antonio on Monday. Many of them had been sprinkled with steak seasoning in a possible attempt by smugglers to ward off authorities, law enforcement officials said.

The sheer scale and disturbing details, including migrants who apparently tried to escape the suffocating triple-digit temperatures inside the truck by jumping to their deaths along several city blocks, were horrific.

Large numbers of fatalities along the most heavily trafficked northbound path from Mexico and...