
It was a morning unlike anything St. Louis had ever seen. Automobile traffic crawled as drivers struggled to peer through murky air. Buses, streetcars and trains ran an hour behind schedule. Downtown parking attendants used flashlights to guide vehicles into their lots. Streetlamps were ignited, and storefront windows blazed with light.
Residents called Nov. 28, 1939, “Black Tuesday.” Day turned to night as thick, acrid clouds blackened the sky. Even at street level, visibility was just a few feet. The air pollution was caused by homes, businesses and factories, which burned soft, sulfur-rich coal for heat and power. The soft coal was cheap and burned easily but produced vast amounts of smoke.