A shelter-in-place order for residents near the Martinez Refining Co. was lifted Saturday night after a fire that injured at least six people. Contra Costa County health officials said they will continue to monitor air quality overnight until they get an all-clear.

The Contra Costa Fire Protection District said six workers at the refinery were injured, and four needed to be hospitalized.

As Contra Costa County Fire and Martinez Refining Company investigators sift through the damage, refinery workers have returned to their posts in an attempt to prevent further incidents, following