Complex sentence: It was renamed Heysel Stadium in 1946, but during the 1985 European Cup final the disrepaired Heysel Stadium became infamous; riots led to the tragic Heysel Stadium disaster, which cost the lives of 39 spectators when Liverpool fans charged a neutral area.
Split into simpler sentences: It was renamed Heysel Stadium in 1946, but during the 1985 European Cup final this new name became infamous. Riots in the disrepaired building led to the tragic Heysel Stadium disaster, which cost the lives of 39 spectators when Liverpool fans charged a neutral area.