Donora Smog of 1948
... that the 20 deaths in the Donora Smog of 1948, called one of the worst air pollution disasters in American history, have been credited with leading to passage of the U.S. Clean Air Act in 1970?
... that the 20 deaths in the <b id="mwFtw"><a class="mw-redirect" href="./Donora_Smog_of_1948" id="mwFt0" rel="mw:WikiLink" title="Donora Smog of 1948">Donora Smog of 1948</a></b>, called one of the worst <a href="./Air_pollution" id="mwFt4" rel="mw:WikiLink" title="Air pollution">air pollution</a> disasters in <a class="mw-redirect" href="./American_history" id="mwFt8" rel="mw:WikiLink" title="American history">American history</a>, have been credited with leading to passage of the U.S. <a class="mw-redirect" href="./Clean_Air_Act_(1970)" id="mwFuA" rel="mw:WikiLink" title="Clean Air Act (1970)">Clean Air Act</a> in 1970?