A large explosion and fire Monday at a natural gas processing plant on the Washington state-Oregon border injured four workers, led to the evacuation of about 400 people from nearby farms and homes, and sent a mushroom cloud of black smoke high into the air
The 8:20 a.m. blast at the Williams Northwest Pipeline plant in the Washington town of Plymouth also punctured one of the facility's two giant storage tanks for liquefied natural gas.
Benton County Sheriff Steven Keane said some gas leaked from the tank to the ground in a moat-like containment area and evaporated into the air, blowing away to the northeast. But it was a relatively small amount, he said.
One of the four injured workers was transported to a Portland, Ore., hospital specializing in burns, he said. The three others were taken to Good Shepherd Medical Center in Hermiston, Ore., where spokesman Mark Ettesvold said they were treated for injuries that did not appear to be life-threatening.