We begin with a warning for every american family packing up the car for one last vacation during these dog days of summer. The price of filling up is about to go up again, way up. Look at this. For... See More
We begin with a warning for every american family packing up the car for one last vacation during these dog days of summer. The price of filling up is about to go up again, way up. Look at this. For weeks, the average price of gas has been on a steady climb. Now, it's about to take off. The week began with news of a 14 cent surge, the biggest one-week jump in a year and a half. Tonight, new signs of trouble, including a fire out west that could spike gas prices across the coast. Abc's neal karlinsky explains. Reporter: You've hear the predictions for months. Tensions with iran, ramped up consumption in china -- even market manipulation were all conspiring to bring you unprecedented gas prices. It turns out the experts should have looked closer to home. Today, the fallout from monday's refinery fire near san francisco sent fuel traders into a panic, and prices through the roof. Just the latest in a string of refinery breakdowns across the country. Up in smoke this time, one of california's biggest gas producer big enough to drive up gas prices at least 25 cents in the next few days up and down the west coast. My husband texted me this morning, said, make sure you get gas because of what happened with the gas refinery. Reporter: So you're filling up to beat the price? Yes. Reporter: In the midwest, it's already worse. In michigan, gas shot up an incredible 34 cents in one week after pipeline ruptures between wisconsin and illinois. And equipment problems closed parts of three refineries in illinois and indiana. When we see these events happen, you know, in such close timing together, the market essentially becomes panics. Reporter: Illinois now has the priciest gas in the nation at $4.09 a gallon, an incredible 30-cent jump in one week. Arizona has the cheapest right now, at $3.25. One problem -- the number of u.S. Refineries has shrunk from 158 to 124 over the lack decade, but those remaining have upped their production -- pumping out 1.5 million barrels a day more. So, each one that goes down packs a much bigger punch to the nation's fuel supply. How long will this price spike last? That depends on the nation's refinery not having more problems and fixing the ones they have now. Companies don't like to give out timelines but it's clear in the midwest it could be several more weeks. Here in california, that refinery could be down for up to several months.
This transcript has been automatically generated and may not be 100% accurate.