The match commander in charge on the day of the Hillsborough disaster has accepted his failure to close the tunnel was the direct cause of the death of 96 people in April 1989.
Giving evidence for a sixth day at an inquest into the disaster, David Duckenfield also admitted he froze when the incident began to unfold at the ground.
ITV News correspondent Damon Green reports from the inquest:
Up to 2,000 fans entered Gate C, with many heading straight for a tunnel in front of them which Mr Duckenfield had not ordered to be closed and then on to the already full central pens on the terrace which led to the fatal crushing.
Paul Greaney QC, representing the Police Federation, put it the retired police chief: "Do you agree with the following, that people died in a crush in the central pens?"
Mr Duckenfield said: "Yes sir."
Mr Greaney said: "That if they had not been permitted to flow down the tunnel into those central pens that would not have occurred?"
The witness repeated: "Yes sir."
The barrister continued: "That closing the tunnel would have prevented that and therefore would have prevented the tragedy."
Mr Duckenfield said again: "Yes sir."
Mr Greaney said: "That you failed to recognise that there was a need to close that tunnel."
Mr Duckenfield said: "I did fail to recognise that sir."
Mr Greaney said: "That failure was the direct cause of the deaths of 96 persons in the Hillsborough tragedy."
Mr Duckenfield replied: "Yes sir."
Answering questions from his own barrister John Beggs QC, Mr Duckenfield admitted it had been the most difficult period of his life to admit his professional failing led to 96 deaths.