Fast response by the Lehighton Fire Department is credited with preventing a potentially major fire in the borough yesterday morning. The fire happened in a third floor apartment of a four-story structure at 256 N. Second St. Captain Pat Mriss of the Lehighton Fire Department said the fire erupted in a trash can. He attributed the cause to careless smoking. The Mahoning Valley and Franklin Township Fire Departments were placed on stand-by status. There were no injuries.