Wikipedia:Today's featured article/November 23, 2017

The 1966 New York City smog (November 23–26) was an air-pollution event, with damaging levels of carbon monoxide, sulfur dioxide, smoke, and haze. Coming during the Thanksgiving holiday weekend, it was the third major smog in New York City, after a similar event in 1953 (pictured) and another in 1963. Leaders of local and state governments announced an alert and asked residents and industry to take voluntary steps to minimize emissions. Health officials advised people with respiratory or heart conditions to stay indoors. The alert ended after a cold front dispersed the smog. It was an environmental disaster with severe public health effects, including 168 deaths, according to a statistical analysis. The smog catalyzed greater national awareness of air pollution as a serious health problem, and became a political issue. With support from presidents Lyndon B. Johnson and Richard Nixon, a series of bills and amendments aimed at regulating air pollution culminated in the 1967 Air Quality Act and the 1970 Clean Air Act.