2013 Event Shanghai officials deliver the highest level health warning as a record level of smog shrouds the city; hundreds of flights were delayed or cancelled 1966 Event 400 die of respiratory failure and heart attack in killer New York City smog 1952 Event Worst smog in London ever, 4-8,000 die 1952 Event Killer fogs begin in London England, "Smog" becomes a word 1948 Event 20 die and 6,000 made ill by smog in Donora Pennsylvania
