New York:  21 tank cars of 120-car Norfolk Southern Corp train carrying heavy Canadian crude oil derailed and spilled in western Pennsylvania on Thursday.The derailed cars  crashed into a nearby industrial building at a bend by the Kiskiminetas River in the town of Vandergrift. Nineteen of the derailed cars were carrying oil, four of which spilled between 3,000 and 4,000 gallons of oil, The train, which originated in Chicago, was destined for an asphalt plant in Paulsboro, New Jersey.