( CNN ) -- Witnesses said a FedEx tractor-trailer truck was already in flames when it crossed a median and slammed into a bus carrying students in Northern California , the National Transportation Safety Board said Saturday night . The driver of a white Nissan Altima that passed the bus just before the crash reported seeing flames coming from underneath the FedEx truck , said Mark Rosekind , an NTSB board member . The truck clipped the car occupied by Joe and Bonnie Duran before it slammed into the bus Thursday evening , killing 10 people -- five high school students , three chaperones and the drivers of both vehicles . More than 30 people , mostly teenagers , were taken to local hospitals . Rosekind , speaking at a press conference , said some bus passengers were ejected from the vehicle , including the ones who died . He said the investigation shows the southbound truck did not brake as it crossed the median at a 10-degree angle and entered the southbound lanes . Investigators found 175 feet of tire marks left by the bus , indicating the driver tried to avoid crashing into the truck . Investigators will look for devices on those vehicles that might provide information about speeds , Rosekind said . One such device -- the electrical control module -- was destroyed by fire on the truck , he said . The electrical control module on the bus survived but `` we do n't know what 's actually on there , '' he said . The truck transmission might also be examined to help determine that vehicle 's speed , he said . Blood samples should be obtained from the bodies of both drivers , which will provide information about whether drugs or alcohol might have been in their systems , he said . Blood samples also might tell investigators if the drivers had inhaled smoke from the fire , he said . He stressed that investigators are only collecting information now and are n't coming to conclusions about the cause of the accident . Bonnie Duran told the CNN affiliate KOVR the truck was on fire before it hit the bus . She said she made a quick decision to swerve to avoid a direct hit from the truck , sending their rental car into a ditch . `` Somehow we survived , '' she said . Her husband said it was like a scene from a movie . `` I looked over and saw the FedEx truck coming straight for me , '' Joe Duran told the affiliate . `` It was like a 3-D movie . Imagine a Mack truck coming out of a movie . '' The Durans were hospitalized and released . Students traveling from the L.A. area . The students were traveling from the Los Angeles area to take part in a program at Humboldt State University , which allows prospective attendees to visit the campus . Their journey ended in the fiery wreck 90 miles north of Sacramento when the truck hit one of three buses taking the teens to the campus in Arcarta . The students on the buses represented 31 Southern California high schools . They were heading to `` Spring Preview Plus , '' which invites low-income and first-generation prospective students to the university . As part of the program , students stay in residence halls , attend events and visit with staff and students from a program that helps historically underrepresented students , the university said . The two other buses in the caravan made it to the university . Those students were placed in dorms , and the university is offering them counseling . Engaged couple among victims of California bus crash .
NEW : Witnesseses tell NTSB the FedEx truck was on fire before hitting bus . `` It was like a 3-D movie , '' said a man in a car that was clipped by the truck . A Joe truck crossed the median , collided with the bus 90 miles north of California . The collision killed both drivers , three students and five chaperones .