After Katrina, I proposed to one oil company to put a 60 foot to 90 foot dirt wall around the refinery to protect against terrorism and storm surge.
It would also contain any explosion within the dirt wall.
The one refinery fire in California was due to a vapor cloud coming contact with a spark from an engine that was idling (fire truck, of all things).
That was the Chevron-Richmond fire. I had not heard of a second refinery fire in California/West Coast.
The other cal fire I believe was at Shell in Martinez last week.
Spark from a Diesel engine?