LOS ANGELES , California -LRB- CNN -RRB- -- Friday 's two-train collision killed 25 people and injured more than 130 others near Los Angeles after an engineer failed to heed a traffic signal , a spokeswoman for Metrolink commuter trains said . A commuter rail car lies on its side after a collision Friday near Los Angeles , California . The engineer was guiding the Metrolink train that slammed head-on into a freight train and is not believed to have survived , Metrolink spokeswoman Denise Tyrrell said on Saturday . `` It was human error , '' Tyrrell said , adding this was Metrolink 's belief `` barring any new information '' from an investigation by the National Transportation Safety Board . NTSB spokeswoman Kitty Higgins said the agency would `` look at everything before we rule anything in or out . '' Tyrrell said the engineer , whom she did n't identify , was a subcontractor employed by another company . She said she did not have details of his record . The crash occurred about 4:30 p.m. PT Friday in Chatsworth , a northwest Los Angeles suburb . The Metrolink train had about 220 passengers and two crew members on board at the time , according to Tyrrell . Watch rescuers search for victims '' Forty-five of the injured were in critical condition , with 40 flown to hospitals , Tyrrell said . Another 50 had minor injuries , and 40 others were treated at the crash site but transported to hospitals for evaluation . `` It was like running into a brick wall at 60 miles an hour , '' an injured passenger told CNN affiliate KABC . In the minutes after the crash , passers-by joined emergency personnel in an effort to free passengers from the wreckage . On Saturday afternoon , Los Angeles Mayor Antonio Villaraigosa said the search of the wreckage had finished . Earlier in the day , authorities were picking through the wreckage and freeing trapped bodies . Ed Winter , assistant chief of the Los Angeles County coroner 's office , told reporters two bodies -- both of females -- had yet to be identified . If the females had carried identification , it probably was lost in the crash , he said . As of 9 a.m. PT Saturday , authorities had been able to notify relatives of eight victims , he said . Gov. Arnold Schwarzenegger visited the crash site on Saturday , telling reporters it was `` one of the worst train accidents in modern history in California . '' The NTSB will make a final determination of the crash 's cause . Higgins , the agency 's spokeswoman , said data recorders have been recovered from both trains , along with a video recorder from the freight train . Higgins said that out of the trains ' five crew members , four survived . Authorities will interview the surviving crew members , Higgins said . Tyrrell said a review of `` a number of programs , '' including the signal system , showed the commuter train 's engineer failed to heed a stop signal , Tyrrell said . `` We do n't know how the error happened , but this is what we believe happened , '' Tyrrell said . The wreck occurred on a curved part of the track where the speed limit is 40 mph , Tyrrell said . She said that just like road vehicles , trains are subject to signal systems . At the wreck site is a siding where one train can wait while another passes , she said . `` They receive a signal to stop and they must hold their location until other traffic has passed , '' she said . Villaraigosa praised police officers and firefighters for working under emotionally draining conditions and treating the victims with respect . `` This has been a grueling night for them , '' he said . The crash sparked a fire that impeded firefighters 's efforts to reach the front commuter car , where most of the injuries occurred , Los Angeles County sheriff 's spokesman Steve Whitmore said . The fire eventually was brought under control . `` We 've already found survivors trapped under fatalities , '' Whitmore said late Friday . Among those killed was Spree Desha , 35 , a Los Angeles police officer on her way home from work , officials said Saturday . `` It 's not unusual for us to respond to disasters , '' said Jerry Szymanski , an assistant commander for the LAPD . `` When we got here , we found it was one that hit close to home . '' Desha had `` mentored and trained a lot of the young officers in the North Hollywood area , '' Szymanski said . Los Angeles County Sheriff Lee Baca said Friday night a sheriff 's deputy was in a hospital 's intensive care unit after collapsing while conducting rescue work . CNN 's Ted Rowlands contributed to this report .