Heysel was a black day in European football. Although it was unfair at the time to solely blame the LFC supporters. Saying that, English football needed a wake up call and the ban that followed definatley helped curb hooliganism to some degree.
If you think that was sad, take a few minutes to watch this documentary about Hillsborough
http://www.liverpoolfc.tv/media/hillsborough_doc_150408_high.asx
It will probably change peoples perceptions of what happened on that horrendous day when we lost 96 supporters