The Great London Smog

London has a long and established history as a very foggy place. And for many centuries, that fog was also very dirty. That is why when the great london smog descended in december of 19 52, nobody quite realized anything unusual was going on. People had been burning coal to heat their homes in london, at least since the middle ages,. This dense, grimy, pea soup fog had been documented all the way back to the 16 hundreds. At its largest, the smog was 30 kilometers, or 18 miles, around london. Before it was gone, it had killed thousands of people.