Chicago trains collide, dozens injured CHICAGO (Reuters) - A Chicago Transit Authority train collided with a standing train at a station in a western suburb of Chicago during Monday morning's rush hour, leaving at least 33 people injured, according to an official with the CTA. The collision happened at about 7:45 a.m. local time at the ground-level Harlem Station in Forest Park west of Chicago, CTA spokeswoman Catherine Hosinski said. Thirty-three people were transported to nine area hospitals with what appeared to be non-serious injuries, including the operator of the standing train, Hosinski said. The National Transportation Safety Board said it was sending investigators to Chicago to investigate the collision. The CTA also is investigating to see whether there was an operator or anyone else on the colliding train, which had no customers. Forest Park Mayor Anthony Calderone gave a slightly higher number of those injured saying forty-eight people had been transferred to 10 area hospitals, adding that none of their injuries was life threatening. "Most of the people were complaining of either neck pain or back pain," Calderone told the CLTV news station. Service had resumed across the affected line by midday, but trains are not stopping at the station where the collision occurred, according to the CTA. Robert Kelly, president of the union which represents train operators, told reporters the moving train was apparently empty and safety mechanisms should have stopped it automatically before it entered the station. "Right now it is starting to look like a mechanical malfunction," Kelly said. Calderone said Forest Park police were treating the station as a crime scene as a precaution to preserve evidence, though they were not saying any crime had occurred. Reporting by Mary Wisniewski; Editing by David Bailey, Jim Marshall and Diane Craft