Tow-truck driver killed helping stranded SUV on train tracks By R. Stickney and Monica Garske, NBCSanDiego.com Video has emerged of a horrific crash in which a tow-truck driver was killed by an oncoming train as he was working to clear a stranded vehicle near the tracks in Southern California. Shaun William Riddle, 27, was struck by a southbound Amtrak train in Cardiff at about 2:35 p.m. PT (5:35 a.m. ET) Saturday while he tried to hook up the vehicle to his truck. The father of two children had been called to the area to help a disabled SUV that had stalled just west of the tracks. The county medical examiner reported that Riddle got back into his truck and tried to move it out of the train's path. He could not move the truck in time and the train struck the truck at a high rate of speed, officials said. More news from NBCSanDiego.com A witness who caught the incident on video said the train crossing arm dropped on the SUV and a moment later, the train slammed into the tow truck. The video shows the truck driver's door closing and then the truck turning away from the train just moments before the collision. Horrific sound It's unclear how fast the train was traveling at impact, but it came to a stop about half a mile away from the crossing. The crash is under investigation. The sound of the fatal crash was horrific, witness Thomas Neely, who works across the street from the train tracks, told NBCSanDiego.com. It's somewhere between an explosion and thunder. You know, when metal hits metal it makes a noise unto itself," Neely said. Another witness said the driver was ejected from his tow truck and thrown some 100 yards from the crash site. Pieces of the truck were strewn around the train tracks for hundreds of yards, including the flatbed, a wheel and even the massive engine block. which landed about 200 yards away.