The wire mills and the zinc works which lined the west side of the Monongahela River were the reason for the existence of Donora, Pa, a small city of fewer than 15,000 people. Everyone worked in the mills or knew someone who did so it was easy to ignore the smells and soot that coated everything with a fine dust especially since the wind usually blew to the east away from the city. The farmers on the other side of the river complained for years about the pollution from the zinc works that was ruining their crops, livestock, and health. The owners of the zinc works claimed it was economically unfeasible to fix the problems.
Then in 1948 disaster stuck Donora. In October an air inversion that lasted for five days trapped pollution in the Donora valley. The haze was so dense that people couldn't see well enough to walk along the sidewalks. Twenty died and at least 5000 had symptoms caused by the pollution. The inversion finally lifted after a rain storm. An investigation by the federal government led to the first national air pollution conference and more involvement by the government to protect the environment and people's health.
The Smog Museum tells the history of Donora and has a lot of information on the inversion. It's curated poorly and could use a complete overhaul. The main exhibits are front page news stories with tiny print which is hard to read and get a good grasp of the events over the five days of the inversion. There are also exhibits about local celebrities, displays of donated items, and wonderful black and white photographs.
The zinc works closed in 1957 and the wire mills closed 10 years later. The city is suffering economically with empty storefronts and streets but there is one bright spot. In the early 1900s Donora Wire and Steel built company housing for their white collar workers using pre-formed and poured concrete, a process developed by Thomas Edison. Eighty houses were built on the hills above Donora (out of the smog range, of course!) and they are in excellent condition today. The museum occasionally conducts walking tours or you can drive along the streets as we did.
The museum is accessible.
Parking is available on the street. The streets in Cement City are narrow and steep. Caution should be used if driving a large RV. Museum 40.17776, -79.85637