October 26, 1948: The Donora Death Fog

It was like something out of a horror movie. But it really happened.

Almost 60 years ago, a fog descended upon the small industrial town of Donora, Pennsylvania. The fog would cover the town over the next four days, killing 20 residents and hospitalizing 7,000 – half the town’s population.

In 1948, the residents of Donora were accustomed to the smoke and smell from the US Steel Corp’s zinc works and steel plants. They accepted the pollution as a fact of life and the cost of employment. But when an inversion set in, trapping the town’s air in the narrow river valley, the residents became trapped in a poisonous mixture of sulfur dioxide, carbon monoxide and metal dust.

At first, the townspeople weren’t alarmed. They carried on with their regular activities, with many even attending a football game, although they couldn’t identify the players or even see the ball through the smog. But within a day, senior residents were unable to breathe, delivery drivers were wearing respirators and the yellow air was starting to burn eyes. Firemen were called to deliver oxygen to residents and a room in the community center was soon the town morgue.

Four days into the siege, the zinc works mill was at last ordered to shut down. The same day, it finally rained and the trapped polluted air was released. The zinc works mill was back in operation the next day.

The Donora Death Fog – or killer smog, as it was also known – triggered the first public calls for protection from industrial air pollution and was the catalyst for the creation of the Pennsylvania Clean Air Act in 1955.