WEST READING (AP) – Federal safety officials are investigating the role of a natural gas pipeline in a fatal blast at a Berks County chocolate factory. The National Transportation Safety Board announced the probe late Tuesday afternoon, calling the incident a “natural gas” explosion and fire. The powerful explosion at R.M. Palmer Co. in West Reading killed seven people, sent 10 to the hospital, and damaged several other buildings. Some workers told relatives they smelled natural gas before the blast, although gas utility UGI said it received no reports of a gas leak. PA State Police have said “everything’s on the table” as fire marshals also try to pinpoint the origin and cause.