Monday morning at 8:20 am, a blast at Williams Northwest Pipeline facility on the Washington-Oregon border injured five workers, and caused some 400 people to evacuate from their homes nearby, as a mushroom cloud of dark black smoke shot up into the sky.
It happened near the town of Plymouth, which sits along the Columbia River. The explosion sparked a fire and punctured one of the facility's two giant storage tanks for liquefied natural gas.
Benton County Sheriff Steven Keane said a relatively small amount of gas leaked from the tank to the ground in a moat-like containment area. But it then evaporated, blowing away to the northeast, he said.
"I think if one of those huge tanks had exploded, it might have been a different story," Keane said.
The fire was extinguished within a couple of hours; however, one if the injured workers had to be transported to a hospital in Portland, OR due to severe burns.
Benton Fire District 1 Capt. Jeff Ripley said another four people were taken to local medical facilities. None of the injuries was believed to be life threatening.
More than a mile away across the Columbia River, the explosion shook local resident Cindi Stefani's home.
"It was just a very loud boom," she said. "I looked across the river and saw a giant mushroom cloud and flames at least a couple hundred feet high."
Animals on neighboring farms were running around frightened, she added.
"At that point we were all pretty scared. I was thinking, 'We need to get out of here.'"
Deputies, who went door to door to homes and farms within a 2-mile radius, evacuated about 400 residents as a precaution.
Williams Northwest Pipeline facility provides gas when needed for high demand. The pipeline reaches a 4,000 mile area that stretches from the Canadian border to southern Utah.
Its two liquefied natural gas storage tanks each have a 1.2 billion cubic foot capacity, Williams spokeswoman Michele Swaner said. The one that was punctured was about a third full.
Swaner said the 14 employees working at the time were all accounted for. A total of 17 or 18 people work at the facility.
She added it was too early to determine the extent of the damage or the cause of the explosion. The pipeline was shut down in the area of the storage facility, but was still carrying gas on other stretches.
Williams operates about 15,000 miles of interstate natural gas pipelines, according to its website.
There was no pipeline rupture, and no customers were affected, company officials said.
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