A fire at a Washington state refinery killed three people and injured four others, the company that owns the refinery said Friday.
The fire at the Anacortes, Washington, refinery occurred shortly after midnight at the naphtha unit of the refinery while maintenance work was being performed, the Tesoro Corporation said.
The fire was contained around 2 a.m. PTÂ (5 a.m. ET) Friday, Tesoro said in a statement on its Web site, and affected units have been shut down.
CNN affiliate KCPQ reported that three workers were missing, and that a search was under way.
The cause of the blaze was not immediately known. KCPQ said people reported feeling an explosion as far as five miles away.
"This is a very sad time for our organization,"Â said Bruce Smith, Tesoro's chairman, president and chief executive officer.
"Everyone in the Tesoro family appreciates the impact that this will have on the families involved, and we are responding quickly to ensure the safety for our employees, contractors and the neighboring community," he said in a statement on the company's Web site.
Tesoro Corporation is an independent refiner and marketer of petroleum products, according to its Web site. Through its subsidiaries, it operates seven refineries in the western United States with a combined capacity of approximately 665,000 barrels per day.
Anacortes is about 80 miles south of Vancouver, British Columbia.