Dallas — A truck driver was sentenced to life in federal prison without parole for a smuggling scheme that ended in the deaths of 10 immigrants who hid in his pitch-dark cargo trailer in the summer heat.

James Matthew Bradley Jr., 61, of Clearwater, Fla., pleaded guilty in October to one count of conspiracy to transport aliens resulting in death and one count of transporting aliens resulting in death.

He was sentenced Friday in a San Antonio federal court, according to the U.S. attorney’s office for the Western District of Texas.

San Antonio police found eight people dead July 23 in a trailer parked behind a Wal-Mart off Interstate 35. Two more people died after they were found, and dozens of others were hospitalized.

There were 39 people found inside the trailer, including four juveniles between the ages of 14 and 17. Some of the occupants told authorities that the trailer had contained as many as 200 people at one point, according to the U.S. attorney’s office.

Temperatures reached 101 degrees that day, and the trailer’s refrigeration system didn’t work. The people in the trailer didn’t have water and all suffered from heat exposure or asphyxiation, police said.

Police had been called to the scene after a disoriented person from the truck asked a Walmart employee for water.