A leak was found beneath the road, in a pipe about 15 feet from the former Hotel Holly.
LEWISTON – Fire investigators believe Monday’s downtown explosion was caused by natural gas, which may have leaked from an abandoned gas line and seeped into the basement of the old Hotel Holly.
Workers for natural gas supplier Northern Utilities discovered a leak late Tuesday in an underground pipe 15 feet from the site of the explosion.
The discovery led fire officials from the city and state to end their investigation into the cause of the blast, which injured five people and demolished the three-story downtown building.
All that remained at the site Wednesday were bits of debris and a charred hole in the ground.
It appears that natural gas collected in the basement of the old hotel, where Lewiston Radiator Works stored radiators, air conditioner condensers and other equipment. Most likely, the gas was ignited by an oil-burning furnace that was operating at the time, said fire Chief Michel Lajoie.
With enough gas inside, Lajoie said, it would take only a tiny spark to create the explosion that was so big it rattled walls in New Auburn.
“It would act like a wick, following the gas in an instant,” said the chief. The fire that followed the explosion was probably fed by pockets of gas.
“After the blast, all three floors fell down into the basement,” Lajoie said. “The building folded onto itself.”
The debris created a shield between firefighters and the burning gas and fed the fire.
At least 10 investigators have been working at the site since the blast and fire, Lajoie said. Among them were a team of five from the State Fire Marshal’s Office, four from the city, at least one from an insurance company and one from Northern Utilities.
On Wednesday, the gas company released a statement saying it plans to continue its own investigation. Until its study is complete, the company would not comment further.
Lajoie said the sheer volume of the debris made it difficult to examine the basement, where the explosion is believed to have happened and the fire begun.
“We were peeling away the layers,” he said.
Beneath the rubble from the upper stories, investigators found empty gasoline tanks and other stored equipment from the radiator shop.
“We have found nothing inside that cellar that would produce that type of explosion,” the chief said. Everything seemed to point to the break in the nearby gas line, which was disconnected from the old hotel about 35 years ago.
Workers from Northern Utilities dug up a portion of Main Street above the line Tuesday, unearthing the place in the line where the gas was capped and the connection with the hotel was severed. The barriers were still in place, said Lajoie.
But less than 10 feet from the cap, gas company workers found the leak and repaired it with a steel ring.
Recent cold weather may have caused a break in the line, the chief said. Dramatic shifts in temperature can cause the ground to move, severing lines.
Lajoie said he has faith in Northern Utilities.
“I am no more afraid of a natural gas leak today than I was before the explosion,” he said.
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