UPDATE/PLYMOUTH, WA - Pipeline safety investigators from the Washington Utilities and Transportation Commission are responding to the natural gas plant explosion near Plymouth.
The UTC investigator, who is a pipeline engineer, will investigate the cause of the explosion and fire after the site is secured. They will also ensure that no evidence is disturbed, and maintain communications with the western region of the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA).
Benton County Deputies say they have evacuated between 300 to 1,000 people. They are planning to send in a robot to make sure it's safe for responding personnel.
Deputies say they don't yet know when residents will be allowed to return home.
PLYMOUTH, WA - A spokeswoman for the Williams Northwest Pipeline plant says all employees were evacuated and have been accounted for following Monday morning's explosion. Michele Swaner says one employee was burned but will recover.
As of 10 a.m. Monday Swaner says it's still too early to determine the extent of the damage or how it happened.
PLYMOUTH, WA - The Benton County Sheriff's Office says the cause of the incident at the Williams Northwest Pipeline Facility was a bursting pipeline, sending a chunk of the pipe into a tank that contains liquid natural gas.
Deputies say they're waiting for the tank to drain in order to start repairs. They say the tank contains a billion cubic feet of natural gas which is still flowing and leaking through the pipe.
Crews have also changed the location of evacuation from the Hermiston Convention Center to the fairgrounds in Hermiston.
Deputies say they have expanded the evacuation area to within two miles of the facility.
Investigators are trying to figure out what caused the pipeline to burst.
PLYMOUTH, WA - Firefighters are evacuating hundreds of people in Plymouth, Washington after a fire and explosion at the Williams Northwest Pipeline facility.
Williams, a natural gas plant, operates two liquefied natural gas tanks across the Columbia River from Umatilla, Oregon.
Firefighters from several agencies are performing a structural strike team response at the facility at 42612 Christie Road. Crews are working from a command post at Highway 14 near Interstate 82.
We've heard reports of at least one injury. No word yet about that person's condition, or about any other injuries so far. Plymouth has a population of around 300 people.
Over the police scanners, one first responder said a 1.2 billion cubic foot natural gas container exploded, which has created a cloud that is evaporating, and heading towards Plymouth.
911 dispatchers are contacting the Paterson, Kennewick and Umatilla School Districts to bring in school buses to help evacuate people to the Fairgrounds in Hermiston.
Dispatchers say they're shutting down Christie Road and Highway 14 surrounding the plant.
Several people living around the Plymouth area, some as far as three miles away, say they felt the explosion and can see the smoke.
We have a reporter headed to the area to learn more. Stay tuned for updates.