We reported previously on last September's PG&E pipeline explosion in San Bruno, California. To update you, there are signs that federal investigators suspect that a weld failure might be one of the causes of that deadly explosion (LAT article). Additionally, the LAT is reporting that state regulators are taking a closer look at pipeline welds on PG&E's system: "The PUC directive calls for internal, X-ray or liquid pressure tests to ensure the integrity of lines not previously examined that are similar in size and age to the pipeline that blew. That line was 30 inches in diameter and more than half a century old. The utility also is required to drop pressure in such lines until the inspections are completed."