An Exxon Mobil spokesman says four contractors suffered minor injuries in an explosion that erupted at a Southern California refinery on Wednesday.
The blast triggered a huge smokestack flare and rained down ash.
Spokesman Todd Spitler says the contractors were taken to a hospital for evaluation.
Fire Department spokesman Steve Deuel said the facility's flare system was triggered to burn off fuel that could add to the fire.
He said the blast happened in a processing facility and the material involved was gasoline.
The facility -- a structure several stories tall -- was shattered. Crews poured water onto the structure afterward but a fire spokesman said at midday the situation was controlled. (AP)
