A fire at one Northern California refinery responsible for 10% of the state's gasoline production has resulted in higher gas prices in California, Arizona and Nevada, highlighting the latter states' reliance on aging California refineries. Last week, the Martinez Refining Co.'s facility caught fire as workers prepared for planned maintenance during the winter season, when demand for fuel is lowest. According to the oil industry, California regulations are responsible for the state's gasoline supply declining rapidly as demand remains strong, creating supply imbalances and price shocks when refineries go down or shut down.