Risk Assessment: Tools, Techniques, and Their Applications

19.1 Introduction

On December 24, 2008, a natural gas leak caused an explosion and fire. It killed one person and injured five others, including one firefighter and a utility worker. The explosion also destroyed one house completely and severely damaged two others adjacent to the destroyed house. Several other houses in the neighborhood were damaged. The neighborhood is located in Rancho Cordova, California. Pacific Gas and Electric Company, the utility owner and operator, operate 42% of California's natural gas pipe lines. According to Pacific Gas and Electric Company, the property damage was $267,000 (1–3).

The incident can be traced back to a phone call that Pacific Gas and Electric Company received on their Customer Contact Center Hotline at 9 : 16 AM. The phone call was made by a resident of 10716 Paiute Way who reported a gas odor outside of her house. The Customer Contact Center prepared a case ticket and contacted the Pacific Gas and Electric Dispatch Office as part of their normal procedures. A field technician received the message and headed toward Paiute Way to investigate the call. On arriving at the affected aforementioned residence, the technician's portable gas detector detected gas on her initial approach across the yard. The technician, equipped only with gas detectors suitable for indoor gas detection, contacted the dispatch office requesting equipment suitable for outdoor gas detection along with the assistance from the maintenance and construction department. ...