Police officer <a class="mw-redirect" href="https://en.wikipedia.org/wiki/Filippo_Raciti" id="mwAVA" rel="mw:WikiLink" title="Filippo Raciti">Filippo Raciti</a> is killed when <a class="mw-redirect" href="https://en.wikipedia.org/wiki/2007_Catania_football_violence" id="mwAVE" rel="mw:WikiLink" title="2007 Catania football violence">a clash</a> breaks out in the Sicily derby between Catania and Palermo, in the <a href="https://en.wikipedia.org/wiki/Serie_A" id="mwAVI" rel="mw:WikiLink" title="Serie A">Serie A</a>, the top flight of Italian football. This event led to major changes in stadium regulations in Italy.