An abundance of fossil fuels combined with advances in technology to harness wind and solar power has sent energy prices crashing around the world. WSJ explains how it all happened at once. Photo illustration: Carlos Waters/WSJ U.S. fuel makers slashed production during the second quarter as they reeled from a historic decline in demand for gasoline and jet fuel. Long a bright spot in the oil patch, refiners such as Valero Energy Corp., Marathon Petroleum Corp. and Phillips 66 pumped the brakes as the coronavirus pandemic kept people off the roads and out of the skies, crushing demand for the fuels they produce. U.S….