Gas prices back on the rise

TORRANCE, CA - An explosion and fire ripped through a gasoline processing unit at an Exxon Mobil refinery down in Torrance, injuring four workers were injured.          According to experts, wholesale gas prices rose six to 10 cents a gallon in California.     The refinery, which employs about 650 employees, produces a specially formulated low-emissions gas that's sold here in California, Arizona and Nevada.      The site produces