NIAGARA MOHAWK POWER CORP

Incident Narrative

AN EXPLOSION OCCURRED AT 310 PAIGE STREET PROMPTING THE SHUTDOWN OF THE GAS SERVICE LINE TO THIS DWELLING. THE ROOT CAUSE OF THE INCIDENT INDICATES THAT THE CAUSE OF THE INCIDENT WAS GAS ESCAPING FROM A FRACTURED GAS LINE INSIDE THE PREMISES, BEYOND THE METER OF THIS PROPERTY LATER FOUND TO BE VACANT. THE LEAK WAS THE RESULT OF TRESPASSERS CUTTING AND REMOVING SEGMENTS OF GAS PIPING INSIDE THE PREMISES PRIOR TO THE EXPLOSION.. THE SERVICE WAS PERMANENTLY RETIRED ON AUGUST 10, 2014.NATIONAL GRID BILLING RECORDS INDICATE THAT THE ELECTRIC AND GAS SERVICES TO BOTH UNITS WERE INACTIVE FROM MARCH 2013 THROUGH THE DATE OF THE INCIDENT. THE GAS SERVICE WAS DISCONTINUED BY THE COMPANY VIA 'SOFT CLOSURE,' WHERE NO MECHANICAL DEVICE OR FITTING WAS INSTALLED AT THE SERVICE VALVE TO PREVENT THE FLOW OF GAS. THE COMPANY USED 'SOFT CLOSURE' BECAUSE THE SERVICE VALVES AND METERS WERE INSIDE THE RESIDENCE, AND THE COMPANY CLAIMS IT COULD NOT GAIN ACCESS TO PHYSICALLY LOCK THEM. A CONTRIBUTING FACTOR TO THIS INCIDENT WAS NATIONAL GRID'S POLICY IN PLACE AT THE TIME AND DECISION NOT TO PHYSICALLY LOCK THE GAS SERVICE LINE VALVES AND/OR PHYSICALLY DISCONNECT THE CUSTOMER PIPING FROM THE GAS SUPPLY, WHEN THE SERVICE WAS DISCONTINUED.