A thick, impenetrable fog engulfed London, shrouding the city in a deadly cocktail of pollution and cold air. The Great Smog, as it came to be known, crippled the city for four days, bringing all forms of transportation to a grinding halt. The Ministry of Health later reported a staggering 4,000 fatalities, making it one of the deadliest environmental disasters in history. The smog's noxious mixture of pollutants and particulate matter turned day into night, making it impossible for people to venture outdoors. As the fog lingered, panic set in, and the usually stoic Londoners were forced to stay indoors, waiting for the fog to lift.