The death toll in a head-on crash of a commuter train and a freight train outside Los Angeles has risen to 24 and more fatalities are expected, officials said on Saturday. The Friday afternoon crash -- the worst commuter train crash in Los Angeles history -- was likely caused by the passenger train engineer's failure to stop at a red light, officials said. “We have confirmed 24 dead and are still working to extricate bodies,” said Los Angeles Fire Department spokesman Ron Myers. The collision also injured 135 people, including 45 who were in critical condition. The Ventura County Line passenger train 111 with 222 passengers aboard smashed into a Union Pacific freight train Friday, near the town of Chatsworth, some 30 miles (50 kilometers) northwest of Los Angeles. “Metrolink has talked about there was some human failure, involved because we never know exactly, whether it was mechanical failure or computer failure or something is wrong with the tracks. They say it was human failure,” Schwarzenegger said. The extent of the devastation and the high number of critically injured passengers taxed the area's emergency response capabilities, Los Angeles City Fire captain Steve Ruda said. Critical patients were flown to area trauma centers. “We utilized every trauma center in the county,” he said. “They're continuing to work in an extrication effort, although we believe the likelihood of anybody being alive in the wreckage at this point is very remote,” Ruda added. Each train was believed to be traveling at the time of the head-on collision at about 37 miles (60 kilometers) per hour. The impact collapsed the first passenger car into its locomotive. “There's no way to describe this train accident other than a tragedy,” Schwarzenegger said earlier, adding that the state will provide emergency response assistance. Metrolink spokeswoman Denise Tyrell said heavy equipment had been brought in to raise the locomotive that derailed and fell onto its side. At least seven cars from the freight train derailed, although most remained standing in accordion fashion across the tracks. The interior of the train was “bloody, a mess. Just a disaster. It was horrible,” passenger Austin Walbridge told a local television news reporter. The crash was the deadliest since the Metrolink crash of January 2005, when 11 people died and dozens injured when a Metrolink train crashed into a Jeep Cherokee parked on train track, derailed and hit a freight train.