flames. The wreckage burned through the night, but the fire was dying down Saturday afternoon as federal investigators began collecting evidence. National Transportation Safety Board spokesman Robert Sumwalt said investigators won't speculate about what may have caused the derailment on the edge of Rockford, about 80 miles northwest of Chicago. A thorough investigation could take a year, he said. Investigators will look into the rail crew's performance, the train's mechanics, signaling, ...