Northwestern Energy blames frost, not negligence, for fatal Montana blast

BOZEMAN, Mont. - Natural external forces, like frost heaving, may have been
responsible for a natural gas pipe failure that caused a fatal explosion in downtown Bozeman last March, Northwestern Energy chief executive officer Bob Rowe said on Aug. 24.
Rowe was seeking to answer the question, at least in his view, of who is liable for the millions that will be required to rebuild half the 200 block of East Main Street in Bozeman.
"What (investigators) are seeing so far is not showing liability on our part," Rowe told about 50 people gathered at the Bozeman Public Library. "If there's a natural occurrence, it's not a liability." Liability is based on negligence, he said.
Although the investigation is still not complete, there is nothing to suggest the service line that failed had undergone gradual deterioration, Rowe said.
The "freshness" of the 7.5-inch crack that went three-quarters of the way around the 2-inch service line, indicated it was caused by "sudden forces" and "very close to the time of the explosion," Rowe said.
As to which came first, the crack in the pipe or the explosion, Rowe said after the meeting: "There may never be a definitive answer."
Rowe acknowledged that the various insurance companies involved in the investigation may have different opinions. "It's probable, rather likely, that conclusions will differ," Rowe said.
And though the mood at the meeting was more than civil - many who had questions for Rowe also thanked him for his company's response to the blast - that didn't deter those people from voicing their frustration.
"It took 15 to 16 hours to turn the gas off two years ago" when there was a significant natural gas leak behind the parking garage construction on East Mendenhall Street, said Mike Hope, owner of the Rocking R Bar that was destroyed in the March 5 blast. "Didn't you learn something then? Was there anything done back then?"

Separated service line blamed for fatal Montana natural gas explosion

BOZEMAN, Mont. - As investigators work to identify the cause of the March 5 gas leak that leveled half a city block, some Bozeman business owners are questioning whether downtown is safe.
Inspectors remain unsure about what prompted a two-inch service line behind Montana Trails Gallery to separate at a coupling about 11 feet from the meter, said NorthWest Energy spokeswoman Claudia Rapkoch.
"There was a physical separation, almost like a break in the line," Rapkoch said. "This was not a pin-hole leak."
Investigators are evaluating variables such as frost and soil composition. The pipe will be sent to a metal lab agreed upon by NorthWestern and private insurers where investigators should be able to identify what prompted the separation.
Many of downtown Bozeman's steel gas lines were installed around 1930, not unusual compared to other communities across the nation, said Rick Kuprewicz, a pipeline expert and president of Accufacts Inc., an energy consulting firm in Redmond, Wash.
In the past two years in central Bozeman, at least two small natural gas leaks in Northwestern's lines have been repaired. One was in a "riser" - a piece of line extending out from the ground near the meter - behind LillyLu Children's Boutique and was repaired in the past several months. LillyLu was one of the businesses destroyed by the explosion.