SOUTHWEST GAS CORP

Incident Narrative

SOUTHWEST GAS WAS NOTIFIED OF A STRUCTURE FIRE AT 3281 SOUTH UPPER TRUCKEE ROAD IN SOUTH LAKE TAHOE, CA. ONCE CREWS WERE ON SCENE, IT WAS DETERMINED THAT NATURAL GAS WAS BLOWING FROM THE METER SET ASSEMBLY. THE LAKE VALLEY FIRE DEPARTMENT WAS ALREADY ON SCENE AND FIRE DEPARTMENT PERSONNEL WERE ABLE TO SECURE THE FLOW OF GAS UTILIZING THE VALVE ON THE RISER (STOPCOCK). SOUTHWEST GAS PERSONNEL ON SCENE CONDUCTED A LEAK SURVEY AND FOUND NO INDICATION OF BELOW GROUND NATURAL GAS READS. ONCE THE FIRE WAS EXTINGUISHED, A FAILURE WAS DISCOVERED ON A 3/4"" STEEL NIPPLE JUST ABOVE THE STOPCOCK. THE APPARENT CAUSE OF THE DAMAGE TO THE METER SET ASSEMBLY WAS SNOW LOAD, BUT THE CAUSE OF THAT LOADING IS UNDER INVESTIGATION. A SUPPLEMENTAL REPORT WILL BE PROVIDED WHEN THAT INVESTIGATION IS COMPLETE. SUPPLEMENT: THE INCIDENT OCCURRED DURING AN EXTREME WEATHER EVENT WITH EXCESSIVE SNOW. THE CAUSE OF THE FAILURE OF THE PIPE NIPPLE WAS THE APPLICATION OF UP TO FOUR SUCCESSIVE DYNAMIC LOADINGS OF SNOW AND/OR ICE FALLING ONTO THE PIPE NIPPLE FROM THE ROOF OF THE RESIDENCE. THE SNOW AND/OR ICE WAS EITHER ""NATURAL FORCE DAMAGE,"" ""OTHER OUTSIDE FORCE DAMAGE,"" OR A COMBINATION OF BOTH. THE PRECISE CAUSE OR CAUSES CANNOT BE DETERMINED DUE TO THE LOSS OF EVIDENCE CAUSED BY THE FIRE AND THE FIRE-FIGHTING EFFORTS.