The smog from the two mills rolled in Oct. 27, 1948, and didn't lift until it rained on Oct. 31. By then, "20 people in Donora had died, and nearly half the town became ill in one of the worst air pollution disasters in the nation's history."
"Over the last two weeks, (Donora residents) marked the 60th anniversary with memorials for the families of those who died".
"We want people to realize Donora was a big part of the environmental movement," said Don Pavelko, a Donora councilman who came up with idea for the museum.
"Smog was not unusual in Donora, a town of 14,000 then that was home to the American Steel & Wire Company and the Donora Zinc Works plants - both run by the United States Steel Company - that sat along the river and employed 5,000 people.
But this was different. The thick, yellowish, acrid smog was the result of an unusual weather inversion - a pocket of warm, stagnant air - that sat over the valley for five days.
Underneath what was essentially a lid on the valley were sulfuric acid, nitrogen dioxide and other poisonous gases, including fluorine, that would normally rise into the atmosphere. Most researchers blame the zinc plant..."