The deadly smog in Donora. It looked like any other foggy weekend in a steel town. Then people started choking. In October 1948, a toxic cloud trapped over Donora, Pennsylvania killed 20 residents and sickened thousands, as industrial emissions mixed with the town’s geography and a freak weather inversion. While the disaster unfolded in just a few days, its impact stretched decades, helping spark the environmental movement that would eventually lead to the Clean Air Act.
—Andrew Daniels, Director of News
