Analysts expect West Coast gas prices to rise beyond $4 a gallon after a fire knocked out a key section of one of the nation's largest oil refineries.
Meanwhile, the same U.S. Chemical Safety Board team that investigated the oil spill in the Gulf Of Mexico was standing by with state and company inspectors waiting for structural and environmental tests to see if it was safe to enter the unit.
In all, five separate investigations will be done to determine the cause and effects of the Monday night blaze at Chevron's Richmond refinery.
"This is an important accident in its own right, it was a large fire and has the potential to affect fuel supplies and prices," said Dr. Daniel Horowitz, a member of the chemical board.
The average price of regular gasoline jumped in California from $3.86 a gallon on Tuesday to $3.94 on Thursday, according to the website GasBuddy.com.
Some experts expect the disruption in production to last for weeks and push prices beyond $4 a gallon.
"It'll depend on Chevron getting their facility repaired," said Patrick DeHaan of GasBuddy.com.