SAN JOSE (KPIX) — Experts are predicting that gas prices in California could stay above $4 a gallon after a refinery caught fire for the second time in as many weeks.

The fire broke out Thursday around 5 p.m. at the Phillips 66 refinery in Carson. The cause of the fire is under investigation.

READ MORE: 8 People Displaced by House Fire in San Lorenzo

On March 15, the refinery caught fire sending a spike in gas prices across the region. Thursday’s fire is expected to cause already high gas prices to creep even higher.

“I think it’s a safe bet to suggest that prices may not be dropping back below $4 a gallon anytime soon,” said Dan McTeague of GasBuddy.

“I think, for the whole state, we’re going to see higher than usual prices and, of course, we’re only a couple weeks away from the Memorial Day long weekend so a bad situation could very well turn out to be worse here.”

READ MORE: UPDATE: Estrada Fire Near Watsonville 60% Contained; All Evacuation Warnings Lifted

McTeague said the damage from Thursday’s fire appears to be far worse than the fire in March but cautions that it may be too soon to say what the long-term effect will be on gas prices until the extent of the damage is known.

He said this is the first time in years California may see prices jump this high because of refinery issues. The state’s average for regular gasoline is $4.09 a gallon. This time last year it was $3.62 a gallon.

If the refinery fire does affect gas prices, drivers won’t see it for several days because of a lag in the system.

Vickie Heads Hall of Fremont said she averages $200 a month on gas and said she feels it in her wallet every time she pays more at the pump.

MORE NEWS: Hayward Woman Killed in Horrific Brentwood Crash

“Every time you go to the gas station it’s ten cents more,” she said. “They think everybody around here works for Silicon Valley and we can afford $5 gas prices when the average person only makes maybe $12, $14, $15 an hour. We don’t make that kind of money and it’s hard on you,” Hall said.