The 1987 King's Cross fire at a London Tube station caused 31 deaths due to a lit match on a wooden escalator, which then spread due to trench effect. see http

The 1987 King's Cross fire at a London Tube station caused 31 deaths due to a lit match on a wooden escalator, which then spread due to trench effect. see https://en.wikipedia.org/wiki/King%27s_Cross_fire https://en.wikipedia.org/wiki/King%27s_Cross_fire and https://www.youtube.com/watch?v=fzM6O0mV5DA https://www.youtube.com/watch?v=fzM6O0mV5DA