PACIFIC GAS & ELECTRIC CO

Incident Narrative

AT APPROXIMATELY 1115 HOURS ON MARCH 3, 2014, A NATURAL GAS EXPLOSION CAUSED MAJOR DAMAGE TO A HOUSE AT GUADALUPE STREET AND 3RD AVE. SW IN CARMEL. A PACIFIC GAS & ELECTRIC (PG&E) CONSTRUCTION CREW TAPPED INTO A 2-INCH DIAMETER STEEL MAIN AND INADVERTENTLY TAPPED THROUGH THE 11/4-INCH DIAMETER PLASTIC MAIN INSERTED IN THE 2-INCH STEEL MAIN. THE CREW WAS NOT AWARE THAT THE 11/4-INCH DIAMETER PLASTIC MAIN HAD PREVIOUSLY BEEN INSERTED INTO THE 2-INCH DIAMETER STEEL LINE. THE CAUSAL EVALUATION OF THE INCIDENT PERFORMED BY A THIRD PARTY INVESTIGATOR DETERMINED THE CAUSE OF THE EXPLOSION TO BE ""INADEQUATE VERIFICATION OF SYSTEM STATUS AND CONFIGURATION WHEN PERFORMING WORK ON A LIVE LINE."" PG&E HAS DETERMINED THAT GAS MOST LIKELY ESCAPED FROM THE 11/4-INCH DIAMETER PLASTIC MAIN AND MIGRATED INTO A SEPARATED SEWER LATERAL THAT PROVIDED A PATH INTO THE HOUSE. NO ONE WAS IN THE HOUSE AT THE TIME OF THE EXPLOSION. A PG&E GAS SERVICE REPRESENTATIVE WAS ON SITE AT 1135 HOURS. PG&E REPAIR CREWS WERE ON SITE AT 1138 HOURS. THE HOUSE WAS NOT OCCUPIED AT THE TIME OF THE EXPLOSION, AND THERE WERE NO INJURIES OR FATALITIES. THE FIRE DEPARTMENT EVACUATED THE HOMES IN A 1-BLOCK RADIUS. DEBRIS FROM THE EXPLOSION FELL ONTO THE ROOF OF A NEIGHBORING HOUSE, AND GAS SERVICE TO THAT HOUSE WAS SHUT OFF AS A PRECAUTION. THE FLOW OF GAS WAS STOPPED AT 1145 HOURS BY SQUEEZING THE MAIN AT TWO LOCATIONS. THE REPAIR CREW ALSO DUG UP AND SQUEEZED THE SERVICE LINE TO THE DAMAGED HOUSE. THE GAS MAIN WAS THEN CAPPED AT 1209 HOURS. THIS INCIDENT WAS REPORTED TO THE DOT AND THE CALIFORNIA PUBLIC UTILITIES COMMISSION DUE TO PROPERTY DAMAGES EXCEEDING $50,000. PG&E CONDUCTED A SPECIAL LEAK SURVEY AFTER THE INCIDENT, AND ONE LEAK ON A SERVICE VALVE IN THE VICINITY WAS FOUND AND REPAIRED. SERVICE TO THE NEIGHBORING HOUSE WAS RESTORED ON 3/11/2014 BY THE HOMEOWNER'S CONTRACTOR WITHOUT NOTIFICATION TO PG&E, HOWEVER, AFTER THE OCCUPANTS INFORMED PG&E ON 3/12/2014, PG&E PERFORMED A SERVICE SHUT DOWN AND RESTART ON 3/12/2014, INCLUDING A PRESSURE CHECK, A SOAP TEST, AND A SAFETY CHECK OF ALL THE GAS APPLIANCES IN THE HOME.