Updated - Adds video - A liquefied natural gas storage tank at a gassification facility in southeastern Washington state exploded early today, injuring four workers and requiring hundreds of nearby residents to be evacuated.
The fire and explosion damaged one of two storage tanks at the facility in Plymouth, Washington on the Columbia River separating Washington and Oregon. The explosion occurred at about 8:22 a.m. Pacific time.
In addition to the estimated 17 Williams workers at the facility, local firefighters said they told residents within a two-mile (3.2 km) radius of the area were told to evacuate.
There are two tanks at the Plymouth facility. Each tank is capable of holding 1.2 billion cubic feet (bcf) of natural gas. Officials at Williams could not immediately confirm how big the storage tanks are.
The United States uses about 71 bcf of gas on average per day.
Michele Swaner, a spokeswoman for facility owners Williams, said they were still investigating the cause of the incident. She said the injured person had burns and they expect him to recover.
She said each tank was about half full, which means that about 0.6 billion cubic feet of gas either burned or escaped into the atmosphere.
Swaner also said Williams shut the connections from its mainline - called the Northwest Pipeline - to the Plymouth facility, but noted that the mainline is still moving gas to customers.
The Northwest Pipeline is a 3,900-mile bidirectional transmission system crossing the states of Washington, Oregon, Idaho, Wyoming, Utah and Colorado. It provides access to natural gas from British Columbia, Alberta, Rocky Mountain, and San Juan Basin in the Four Corners region.
The fire started at the facility and was followed by an explosion in one storage tank, said Ed Dunbar, a captain with the Benton County Fire District office.
To create LNG, natural gas is cooled to minus 260 degrees Fahrenheit at which point it condenses into a clear, odorless liquid, according to Williams' website. The LNG is stored in large tanks, built with a double-wall design, Williams said.
Williams also operates LNG facilities in Pine Needle, North Carolina, and in New Jersey off its Transco pipeline.