Hooliganism had affected the sport for some years, and was particularly virulent in England.
A report by Eastwood & Partners for a safety certificate for the stadium in 1978 concluded that although it failed to meet the recommendations of the Green Guide, a guide to safety at sports grounds, the consequences were minor.
The panel's report resulted in the previous findings of accidental death being quashed, and the creating of new coroner's inquests.
It also produced two criminal investigations led by police in 2012: Operation Resolve to look into the causes of the disaster, and by the Independent Police Complaints Commission (IPCC) to examine actions by police in the aftermath.
In the days and weeks following the disaster, police fed false stories to the press suggesting that hooliganism and drinking by Liverpool supporters were the root causes of the disaster.
Blaming of Liverpool fans persisted even after the Taylor Report of 1990, which found that the main cause of the disaster was a failure of control by South Yorkshire Police (SYP).
The disaster also led to a number of safety improvements in the largest English football grounds, notably the elimination of fenced standing terraces in favour of all-seater stadiums in the top two tiers of English football.
Reporting in 2012, it confirmed Taylor's 1990 criticisms, while also revealing new details about the extent of police efforts to shift blame onto fans, the role of other emergency services, and the error of the first coroner's inquests.
This left planning for the semi-final match to Duckenfield, who had never commanded a sell-out football match before, and who had "very little, if any" training or personal experience in how to do so.
In October 1988 a probationary PC in Mole's F division, South Yorkshire was handcuffed, photographed, and stripped by fellow officers in a fake robbery, as a hazing prank.
Four officers resigned and seven were disciplined over the incident.
It emphasised the general situation at Hillsborough was satisfactory compared with most grounds.
Risks associated with confining fans in pens were highlighted by the Committee of Inquiry into Crowd Safety at Sports Grounds (the Popplewell inquiry) after the Bradford City stadium fire in May 1985.