The 1985 disaster at Bradford City Stadium.
Today in Groningen the match between the local FC and Ajax was canceled. Some idiots not only threw toilet paper on the pitch (they do that everywhere), but they set fire to the paper first. A big fire was the result. (Soccer 365)
Twenty were injured, nobody was killed. In Bradford, twenty three years ago 56 people were not so lucky. Within a few minutes the whole stand went on fire. Click on the picture to see the report from back then.