From the comments
Most sensible people don't think the Liverpool supporters were wholly to blame for the Heysel tragedy. Liverpool, like most major English (and Italian) clubs at the time, contained a substantial hooligan element. The type of terrace invasion which triggered the Heysel disaster was regular feature of football during the 1970's and 1980's. Looking back, the surprise was that something similar hadn't already happened. However, what irritated many was the apparent reluctance of Liverpool Football Club to accept any responsibilty & the ludicrous assertion by the club chairman that the hooliganism on that day was caused by the National Front.
That is it all in a nutshell