WEST READING (AP) – Federal safety investigators are looking at a natural gas pipeline for fractures and other damage as they gather evidence on the cause of a deadly explosion at a Berks County chocolate factory. The National Transportation Safety Board opened a probe into the blast at R.M. Palmer Co., which killed seven, wounded several others, and leveled the West Reading building. Safety investigators are gathering evidence about the pipeline. A preliminary report on the explosion could be available in about three weeks, whereas the final report could take up to two years. The family that owns the factory says the loss of their employees “will be felt forever.”