LOS ANGELES (AP) — A trucker who fell asleep behind the wheel was sentenced to four years in state prison after he pleaded guilty to causing a tour bus crash on a Southern California freeway that killed 13 people in 2016, officials said. Bruce Guilford of Covington, Georgia, faced 42 charges of reckless driving and vehicular manslaughter. John Hall, a spokesman for the Riverside County District Attorney's Office, said Guildford pleaded guilty to all counts Friday. Guilford entered his plea directly to the Riverside County Superior Court, meaning he did not work out a deal with prosecutors and had to plead guilty to all counts. Authorities say Guilford fell asleep after utility work briefly halted traffic on Interstate 10 near Palm Springs. His truck did not begin moving when traffic started flowing again. The tour bus, carrying gamblers back from a desert casino, slammed into the rear of his truck at 76 mph (122 kph), killing the bus driver and a dozen passengers. Twenty-nine people were injured. Officials said Guilford had fallen asleep after he illegally drove for too many hours. Investigators had determined that in the four days before the crash, Guilford had driven well over the permitted maximum number of hours, tried to hide the violations by falsifying his daily log and had, at best, only seven possible hours of sleep in the 24 hours before the crash. Prosecutors had asked the judge in a sentencing memorandum to give him the maximum penalty of 32 years and eight months, Hall said.