Five years ago a natural gas pipeline exploded in San Bruno. The resulting fireball destroyed a neighborhood and killed eight people. PG&E, the owner of the pipeline, faces hundreds of lawsuits, a $1.6 billion penalty and more than two dozen criminal charges for negligence. An effort to block PG&E from claiming a $115 million tax break for the penalty failed on Thursday. We'll look at San Bruno's recovery efforts, how the explosion served as a wake-up call for pipeline safety, and learn about a KQED investigation into the cozy relationship between PG&E and its regulators.