A former chief constable has told the inquest into the deaths of 96 Liverpool fans that he recognised "within minutes" the Hillsborough tragedy was not a pitch invasion as initially believed by police.
Ken Jones, a sergeant with South Yorkshire Police in 1989, was among officers who answered the call for all available personnel to go to the ground shortly after the kick-off of the FA Cup semi-final, as fans were crushed in the central pens at the Leppings Lane end of the ground.
Mr Jones said the impression given on the radios was that there had been a pitch invasion and "possible disorder".
But the witness said when he walked on to the pitch at about 3.10pm on April 15 1989 he was "shocked" at the scene which greeted him and added it was "obvious" a major incident should have been declared by that point.
He said he a saw a "thin" police cordon of up to 30 officers midway on the pitch when he entered the ground's Penistone Road entrance.
Mr Jones told the hearing in Warrington: "It was not a committed group of officers with a settled purpose. They were confused. I thought some of them looked dazed.
"It was clear that there were people moving between gaps in this cordon, and as I now know, with people who were either terribly injured or deceased."
Counsel to the inquests Christina Lambert QC asked him: "Not a pitch invasion?"
Mr Jones, who said he had lengthy experience of pitch invasions, said: "I think within minutes I took the view that this was not a pitch invasion and this was not disorder in the sense that there were people fighting."
He recalled moving to the stadium's gymnasium about 15 minutes later where a casualty bureau was in the process of being set up and said it was then the seriousness of the situation "dawned on us".
Mr Jones said: "My recollection is of a lot of very distressed people, a lot of angry people, a lot of very anxious people and police officers, more senior, at that point trying to establish some control and order."
He said he thought there were insufficient medical resources to help casualties.
Stephen Simblet, representing some of the bereaved families, asked:
"Would you agree with me that the scene you saw at about 3.10pm somebody should by then have declared this as a major incident, it is obvious that it needed to be done?"
Mr Jones replied: "It was obvious, yes sir."
The witness said police radios during the tragedy were "under immense pressure" which affected communications between officers and other parts of the operation.
He agreed with Fiona Barton, representing South Yorkshire Police, that it was "common knowledge" in the late 1980s that radio functionality was often inadequate during a major incident.
Miss Barton said: "It was undesirable for a radio message to give a great deal of details because chances are it would cut off?"
"That's correct," said Mr Jones.
John Beggs QC, representing three retired match commanders, noted that Mr Jones had made a witness statement two days after the disaster in which he wrote about his efforts to help fans from the pens at the Leppings Lane.
Mr Jones stated: "I was kicked and verbally abused as more fans came on to the pitch. It was apparent they were intent on charging the Notts (Forest) end."
He went on to say he formed part of a cordon across the halfway line as a result.
In his statement, he continued: "The aggressive and selfish behaviour of the released fans obliged us to deplete the rescue effort for fear of a greater tragedy developing at the Notts end had a charge taken place."
Later he said that as he returned to the Leppings Lane end, "fans were still charging around attacking and abusing officers who were vainly trying to revive/assist injured people."
Mr Beggs asked the witness why officers from Operation Resolve, the criminal investigation into the disaster, had not made reference in their interviews with him to his "most contemporaneous account".
Mr Jones said: "I can't answer that. It was not shown to me."
The witness recalled attending a pre-match briefing in March 1989 which was chaired by then chief superintendent Brian Mole and also attended by his eventual successor later that month, David Duckenfield - the match commander for the fateful semi-final.
The inquests have heard that minutes of that meeting have not been traced.
Mr Jones said he would have expected the records to have been kept.
He said: " I am aware that file cannot be traced by the Independent Police Complaints Commission. It is a matter of great concern to me because those types of documents I think will greatly assist the coroner and the jury in questions they have to answer."