Four cars of a train carrying vehicles went off the tracks in Gardner Wednesday afternoon. Gardner Fire Lieutenant Michael Boris said that the derailment occurred shortly before 3:45 p.m. and that no one was injured. Boris said he did not know whether any of the vehicles were damaged or what happened to the workers after the incident. It was not immediately known what caused the derailment. The company operating the trains was the Providence and Worcester Railroad Co., Boris said.Travis Andersen can be reached at email@example.com. Follow him on Twitter @TAGlobe.