A Metra commuter train struck several vehicles during the holiday rush hour in suburban Chicago Wednesday, injuring at least 13 people, a company spokesman said. One of the vehicles burst into flames. The train struck five vehicles at a busy intersection, setting off a chain reaction that ultimately involved about a dozen vehicles in this Chicago suburb, Metra spokesman Patrick Waldron said. Metra spokeswoman Judy Pardonnet said at least three people in the vehicles were in critical condition. Waldron said there appeared to be no injuries among passengers aboard the express train, which was headed from Chicago to Antioch, near the Wisconsin border when the crash occurred at about five pm. (2300 GMT). The rail crossing cuts through a busy diagonal intersection. A street sign beside the tracks reads, "Long crossing. Do not stop on the tracks." Greg Sandford said he had driven across the tracks when he saw the accident. "The van in front of me stopped short and I stopped short and, 30 seconds later, the Metra train just plowed through," said Sandford, a 27-year-old engineer from Chicago. "The train hit maybe six or eight cars and they hit other cars and they careened into my car," said Sandford, adding that there were no flashing lights at the tracks when he crossed. Lee Sartucci of Elmwood Park was walking in the area shortly after the accident. "I saw one car burning on the tracks," he said. Four people taken to one area hospital had not sustained life-threatening injuries. The conditions of the others injured was not immediately clear.