9. Workers washing the smog-blackened exterior of Allegheny Courthouse
14. Wabash Bridge (now demolished) and unidentified Downtown church during midday
15. Around the same time, St. Louis was also fighting to reduce air pollution
18. For more about pollution in that era, read about the Donora Smog, which killed 22 people and sickened more than 5,000 in 1948.
- Robert L. Dear was identified as the suspected gunman in a fatal shooting at a Planned Parenthood in Colorado Springs. ›
- World leaders will meet in Paris starting Monday to discuss a potential global climate change agreement. Here's what you need to know. ›
- And how well do you know what happened in the news this week? Take our quiz. ›