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.

CPUC and PG&E Emails: "Focus elsewhere for the moment"

CPUC and PG&E Emails: "Are you bringing Charlie's Angels too?"

CPUC and PG&E Emails: "Any thoughts - non-attributed of course"

• More: Bill Blocking PG&E From Deducting $115 Million of San Bruno Fine Fails
• More: Five Years After Deadly San Bruno Explosion: Are We Safer?
• More: How San Bruno Families Remember, and Recover From Disaster
• More: 10 Emails That Detail PG&'s Cozy Relationship With Regulators