Back in the days when escalators were made of wood, often had piles of inflammable litter built up behind them, and still had smokers flicking their smoldering cigarette butts all over the place.<p>There was a huge investigation into the causes of the King&#x27;s Cross fire, and many changes implemented as a result [0]. The investigation even led to the discovery of the Trench Effect [1] &quot;a combination of circumstances that can rush a fire up an inclined surface&quot;.<p>[0] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;King%27s_Cross_fire" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;King%27s_Cross_fire</a><p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Trench_effect" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Trench_effect</a>