At least 10 times since 2008, freight trains hauling oil across North America have derailed and spilled significant quantities of crude, with most of the accidents touching off fires or catastrophic explosions. The derailments released almost 3 million gallons of oil, nearly twice as much as the largest pipeline spill in the U.S. since at least 1986. And the deadliest wreck killed 47 people in the town of Lac-Megantic, Quebec. Those findings, from an Associated Press review of U.S. and Canadian accident records, underscore a lesser-known danger of America’s oil boom, which is changing the global energy balance and raising urgent safety questions closer to home. Experts say recent efforts to improve the safety of oil shipments belie an unsettling fact: With increasing volumes of crude now moving by rail, it’s become impossible to send oil-hauling trains to refineries without passing major population centers, […]