U.S. regulators are urging railroads to change the way they deal with wheel defects, saying the problem may have caused a fiery oil-train derailment in Illinois last month. Despite multiple warning signs, a train carrying crude oil from North Dakota to Philadelphia continued to travel on a potentially faulty wheel, according to a preliminary federal investigation. Twenty-one cars of a BNSF Railway Co. oil train derailed near Galena, Ill., 160 miles west of Chicago. Several cars ruptured during the accident and the oil inside caught fire, generating large explosions. On Friday, the Federal Railroad Administration issued a safety advisory pointing to a broken wheel and telling railroads to act more aggressively to fix […]