Why was London in the novels of Dickens and about Sherlock Holmes so famous for its fog? We nicknamed it 'Pea Soup', it was a yellow smog from burning coal, and a lot of people died from breathing it in. It came to a head in the Great Smog of 1952. Ducks were crashing blindly through the windows of Victoria station, public performances were being cancelled because of the incessant coughing, around 12,000 people died over a few days. After that using coal for domestic fires in urban areas was banned and the historical Clean Air Act was passed in 1956.’