California oil refinery

An explosion rocked an Exxon Mobil refinery on Wednesday morning, triggering a huge smokestack flare, raining down ash and leaving four with minor injuries, company and local officials said.
Workers fled the area, ABC news reported Wednesday.
The facility — a structure several stories tall — was shattered. Crews poured water onto the structure afterward, and a fire spokesman said at midday the situation was controlled.
The blast happened in a recently installed processing facility and the material involved was gasoline, said Fire Department spokesman Steve Deuel.
The facility's flare system was triggered to burn off fuel that could add to the fire, Deuel said.
Residents within a mile or two reported feeling a sharp jolt that they initially thought was an earthquake.