The risk of death from crushing at Hillsborough was "obvious, serious and present" throughout the failings of match commander David Duckenfield, a court has heard.
On Wednesday, the prosecution continued opening the trial of Duckenfield, 74, who denies the gross negligence manslaughter of 95 Liverpool fans, and former Sheffield Wednesday club secretary Graham Mackrell, 69, who denies contravening a condition of the ground's safety certificate and a health and safety offence.
Richard Matthews QC, prosecuting, told Preston Crown Court the arrangements at the FA Cup semi-final on April 15 1989 meant 10,100 Liverpool fans with tickets for the terraces had to get through seven turnstiles at the Leppings Lane end of the ground - making it "obviously identifiable" as a bottleneck for spectators.
He said it was an "extraordinary failure" for Duckenfield not to have personal knowledge of the potential confining points and hazards to safe entry at the stadium.
He said: "That is why is such personal knowledge is obviously central and essential to discharging the responsibility of match commander, because it was, the prosecution say, so obvious a risk to people's lives."
Mr Matthews said it involved "no hindsight" to recognise there was a need to prevent too many people entering the confined area of the central pens of the Leppings Lane terrace, where the fatal crush happened.
He said: "The Crown's case, and will ultimately be a matter for you to decide, but the Crown say that the risk of death was obvious, serious and present throughout the failings of David Duckenfield to show reasonable care."
The court was shown video footage of an FA Cup semi-final held at Hillsborough in 1981 when police let Tottenham Hotspur supporters out through pitch perimeter gates after an incident of crushing on the Leppings Lane terrace.
Mr Matthews said the court would hear some evidence that during that incident police blocked off access to the terrace to stop any more spectators from entering.
The jury was told the stadium safety certificate, issued in 1979, included a capacity figure for the terrace which expert John Cutlack had estimated was too high by almost 2,000.
He said Mr Cutlack believed alterations to the terrace, including the removal of crush barriers and the introduction of radial fences to make pens, meant the area's capacity was 5,426 rather than 7,200.
Mr Matthews said by the time of the disaster the safety certificate was "very out of date".
Duckenfield, of Bournemouth, who wore a grey suit and purple shirt with spotted tie, sat in the well of the court for the third day of proceedings, alongside lawyers and co-defendant Mackrell.
Under the law at the time, he can not be charged with the death of the 96th victim, Tony Bland, as he died more than a year and a day after sustaining injuries in the crush at the match between Liverpool and Nottingham Forest.
Mackrell, of Stocking Pelham in Hertfordshire, is charged with contravening a term or condition of the stadium's safety certificate, by failing to agree the methods of admission for the match, and failing to discharge a duty under the Health and Safety Act by not taking reasonable care in respect of arrangements for admission and the drawing up of contingency plans.
The prosecution opening of the case will continue on Thursday.