OMG! OMG! This is BEFORE global warming!!(it's still the republican's fault...........)-------The Fog That Killed 12,000 People

The Fog That Killed 12,000 People - KnowledgeNuts
In 1952, weather conditions led to a massive smog descending on and gathering over London.
Visibility was less than 30 centimeters (12 in), the air was black with coal and pollution, and the usually bustling city ground to a standstill. 
By the time the smog had cleared, 4,000 people had died from exposure to the pollution, and another 8,000 would die in the following weeks from complications. 
The smog would lead to increased awareness of the problems of pollution over city centers.