Stacey is right, race relations in the town were indeed strange, but it didn't seem to bother anyone much, apparently not even black residents.
diversity
Social Life in 1940s Donora
For decades during the mid-1900s a Chamber of Commerce sign at the Donora town line read, “NEXT TO YOURS THE BEST TOWN IN THE USA.” Donorans found an odd pride in being a second-best town, no matter where a visitor came from. Perhaps that was to be expected. The town didn’t originate naturally, as a place people moved to because they liked the area or as a natural outgrowth of an urban area. No, it originated because industrialists in Pittsburgh thought it would make the best spot to build steel and zinc mills.