COLUMBIA FALLS – NorthWestern Energy officials met here Wednesday to release the findings of an investigation on the May 6 house explosion that killed one of its employees.
The energy company also wanted to meet with Columbia Falls city officials to thank them for their response to the blast.
The investigation concluded that a Flathead Electric Cooperative backhoe operator hit an unmarked three-quarter-inch gas service line near the intersection of Second Avenue West and 12th Street West, according to NorthWestern Energy.
The backhoe pulled the line off its welded connection to a service tee on the nearby gas main, and gas from the broken connection migrated through the soil on the path of the sewer line and into the basement of Ted and Myrtle Langton’s house, at the southwest corner of the intersection.
The collected gas exploded after being ignited by an unidentified source, NorthWestern Energy officials said.
The blast killed NorthWestern Energy journeyman serviceman Jim Hilton, 53, of Kalispell, who had responded to the call of the broken gas line.
“It was really a tough situation for us because we lost an important employee,” Bob Rowe, President and CEO of NorthWestern Energy, told city officials.
According to NorthWestern Energy, the gas main runs underneath Second Avenue West. Two service lines branch perpendicularly off the main line; the service line to the Langton’s house tees west off the main line and connects to the meter on the south side of the house. This line was located and marked by ELM Locating and Utility Services a week prior to the explosion.
The backhoe, however, damaged the second service line splitting off the main line, which runs to the Langton’s neighbor’s house. The locating services had reportedly not performed a “locate” for this line prior to the accident, according to the energy company.
Flathead Electric Cooperative spokeswoman Wendy Ostrom Price said the Co-op sent a request to the UDIG center in the week prior to the dig, and they received confirmation of the request.
“When our crew got to the job, it was clear the the locaters had been there, because there was paint marking the main gas line,” Ostrom Price said. “There was paint that said ‘OK’ on our power pole.”
“But the fact is, the line that we hit had not been marked,” Ostrom Price said.
Investigators went back to the scene on May 27 and cleared debris from the basement of the destroyed house to conduct gas and air migration tests.
After these tests, investigators excavated the gas piping where the damaged service line connected to the main gas line. Visual inspection confirmed that the service line had been torn off the service tee when the backhoe snagged it, according to NorthWestern Energy.
Investigators documented the basement and exposed sewer lines at the blast site. They also took soil samples adjacent to the leak site.
Each NorthWestern Energy official present at the meeting with city officials praised Columbia Falls and its emergency responders for their work at the explosion.
“The people in this community have been very supportive in this tragic event,” Jason Merkel, NorthWestern Energy’s general manager for Montana operation, said. “Thank you.”
Rowe also thanked the city’s work, and stressed that the NorthWestern Energy employees in the Flathead are highly qualified and valued parts of the company. Losing one of them sent ripples throughout the whole company, he said.
“When something like this happens, people really come together,” Rowe said.
Columbia Falls Mayor Don Barnhart took a turn to thank NorthWestern Energy for their response to the explosion, as did city Fire Chief Rick Hagen.
Though the investigation is now complete, NorthWestern Energy officials noted that the healing process for the Hilton and Langton families would continue.
As part of a legacy for Hilton, his wife set up a memorial fund for him with Energy Share of Montana. The fund will help natural gas customers in the Flathead Valley pay their bills.
So far, about $2,000 in donations has been made to the fund, NorthWestern Energy officials said, and the company will match contributions up to $5,000.