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 sense, it worked the way it was supposed to."
Fire/Rescue Marshal Dirk Johnson confirmed there was no gas leak in downtown Great Falls, and corroborated Energy West's report of cards scented with mercaptan, the chemical added to natural gas to give it a smell of rotting eggs, being responsible for the aroma.
As the garbage truck drove around downtown it left behind the smell of natural gas," Johnson said.
Before the incident was resolved, several downtown buildings were evacuated, the newspaper said.