CONSUMERS ENERGY CO

Incident Narrative

AN EXCAVATOR WAS DIGGING WITH A BACKHOE AT THE NORTHEAST CORNER OF THE HOUSE AT 3116 VIENNA ROAD IN CLIO, MICHIGAN ON JULY 30, 2013 WHEN THE MACHINE'S BUCKET PULLED AND DAMAGED THE 1-1/8"" PLASTIC MEDIUM PRESSURE SERVICE TO THE HOME. THE SERVICE HAD BEEN STAKED PROPERLY PRIOR TO THE EXCAVATION, BUT THE DAMAGING PARTY FAILED TO HAND EXPOSE THE FACILITY DURING EXCAVATION. THE CUSTOMER AT THE HOME NOTIFIED CONSUMERS ENERGY OF THE DAMAGE AT APPROXIMATELY 13:08 HOURS OF THE DAMAGE, INDICATING THAT ODOR WAS IN THE AIR AND THAT HISSING COULD BE HEARD. CONSUMERS ENERGY'S FIRST RESPONDER ARRIVED AT THE SCENE AT 13:41, BRIEFLY ASSESSED THE EXCAVATION AREA AND THE DAMAGED SERVICE, THEN RETURNED TO HIS VEHICLE TO NOTIFY DISPATCH AND CALL FOR A GAS DISTRIBUTION CREW. AFTER CALLING DISPATCH, THE FIRST RESPONDER EXITED HIS TRUCK, AND AT THAT TIME THE HOUSE EXPLODED (APPROXIMATELY 13:45). THE EXPLOSION RESULTED IN THE DEATH OF TWO CUSTOMERS AND THE HOSPITALIZATION OF A THIRD, ALL OF WHOM WERE IN THE HOME AT THE TIME OF THE EXPLOSION. FOLLOW-UP INVESTIGATION REVEALED THAT THE BACKHOE BUCKET PUNCTURED THE SERVICE, THE DAMAGE OCCURRING APPROXIMATELY 8 FEET FROM THE RISER. ADDITIONALLY, INVESTIGATORS BELIEVE THE HOOKING AND LIFTING MOTION SEPARATED THE SERVICE FROM THE RISER AT A FUSE ON A REDUCER CONNECTING THE 1-1/8"" SERVICE TO THE 5/8"" RISER. ADDITIONALLY, FOLLOW-UP INVESTIGATION HAS IDENTIFIED TWO POSSIBLE PATHS OF MIGRATION FROM THE DAMAGED FACILITY TO THE HOME: 1.) A CRAWL SPACE VENT, DIRECTLY BENEATH THE GAS METER LOCATION; AND/OR 2.) THE FOUNDATION OF THE HOME, CONSISTING OF LARGE RAILROAD STONES (4' WIDE BY 3' DEEP) AND POTENTIALLY MORE POROUS THAN OTHER FOUNDATION MATERIALS. THE CRAWL SPACE BENEATH THE HOME HAD A DIRT FLOOR. THE SOURCE OF INGITION IS UNKNOWN.