GREAT FALLS, Mont.- The smell of a suspected natural gas leak in Great Falls, Mont., Wednesday was traced to discarded scratch-and-sniff cards, a gas company manager said. The numerous reports of the distinctive aroma of natural gas were acted upon by the city's Public Service Commission, the Great Falls Tribune reported. The cause, though, was boxes of scratch-and-sniff cards designed to educate customers what a gas leak smells like. The cards had been thrown out, then hauled away and compacted in garbage trucks, Nick Bohr, general manager of Energy West, said. There's no problem with contamination," Bohr said. "In a...