MONTANA - DAKOTA UTILITIES CO

Incident Narrative

ON 3/5/2018 AT 14:45 MST A TRAILER HAULING A CAR DETACHED FROM A PICKUP TRUCK HITCH LEFT THE ROAD WAY AND CROSSED THROUGH ROAD DITCH, ACROSS ROW BERM AND CRASHED INTO A GROCERY STORE LOCATED AT 747 TIMMONS BLVD. THE DETACHED TRAILER STRUCK THE BUILDING'S PAD MOUNTED ELECTRICAL TRANSFORMER AND SURROUNDING FENCE. THE FLYING DEBRIS FROM THE ACCIDENT DAMAGED THE ABOVE GROUND GAS METER SET RESULTING IN GAS RELEASE AND IGNITION OF A FIRE AT THE METER LOCATION ON THE SIDE OF THE BUILDING. AT APPROXIMATELY 15:00 MDU SERVICE TECHNICIAN ARRIVED ON SCENE THE SAME TIME AS RAPID CITY FIRE DEPARTMENT. MDU CONSTRUCTION PERSONNEL ALONG WITH MDU SUPERVISORS ARRIVED BETWEEN 15:15 AND 15:30. LOCAL SUPERVISION INFORMED MDU GENERAL OFFICE OF THE ACCIDENT AND IT WAS DECIDED THAT DUE TO THE RELEASE AND DAMAGE RESULTING IN POSSIBLY MORE THAN $50,000 OF DAMAGE THAT A REPORT WAS MADE TO NRC AT 15:30. GAS RELEASE WAS CONTROLLED AT 16:05 WHEN THE 4"" MDPE MAIN THAT PROVIDED THE FEED TO THE STORE'S SERVICE LINE WAS SQUEEZED OFF. A FOLLOW UP REPORT WAS SUBMITTED TO THE NRC ON MARCH 6, 2018 AT 11:44. THE FOLLOW UP REPORT NUMBER IS 1206023. A NEW METER SET WAS CONSTRUCTED AND INSTALLED PRIOR TO SERVICE BEING COMPLETELY RESTORED TWO DAYS AFTER THE ACCIDENT ON 3/7/2018 AT 15:06 WHEN THE BUILDING'S NON-JURISDICTIONAL APPLIANCE PIPING DOWNSTREAM OF THE METER HAD BEEN REPAIRED AND INSPECTED BY THE LOCAL JURISDICTION. THIS EVENT RESULTED IN NO INJURIES OR FATALITIES, AND ONLY THE AFFECTED GROCERY STORE WAS TAKEN OUT OF SERVICE AS A RESULT OF THE ACCIDENT.