Security blunders at the Manchester Arena led to a failure to prevent or minimise the devastating impact of the suicide bombing that killed 22 people and injured hundreds at the end of an Ariana Grande concert, a report has found.

Sir John Saunders, chairman of the public inquiry into the terror attack, highlighted a string of “missed opportunities” to identify Salman Abedi, 22, as a threat, before he walked across the venue’s City Room foyer and detonated his shrapnel-laden device as thousands left the concert at 10.31pm on May 22 2017.

He said: “Had that occurred, I consider it likely that Salman Abedi would still have detonated his device, but the loss of life and injury is highly likely to have been less.

“No-one knows what Salman Abedi would have done had he been confronted before 10.31pm.

“We know that only one of the 22 killed entered the City Room before 10.14pm.

“Eleven of those who were killed came from the Arena concourse doors into the City Room after 10.30pm.”

Manchester Arena Inquiry
The 22 victims of the terror attack during the Ariana Grande concert at the Manchester Arena in May 2017 (GMP/PA)

Retired High Court judge Sir John ruled Arena operator SMG, its security provider Showsec and British Transport Police (BTP), who patrolled the area adjoining Manchester Victoria rail station, were “principally responsible” for the missed opportunities.

He added: “Across these organisations, there were also failings by individuals who played a part in causing the opportunities to be missed.”

Sir John concluded the “most striking” missed opportunity involved a member of the public, Christopher Wild, reporting Abedi to a Showsec steward about 15 minutes before the explosion.

Mr Wild and his partner, Julie Whitley, were waiting to pick up her daughter and her friend.

They spotted Abedi and Mr Wild was concerned about his bulging rucksack and worried he might “let a bomb off”.

He reported Abedi to steward Mohammed Agha at 10.15pm, but was “fobbed off”.

Manchester Arena bombing
Salman Abedi on the night he carried out the Manchester Arena terror attack (GMP/PA)

That Mr Agha did not take Mr Wild’s concerns seriously, and act immediately by reporting the matter to supervisors, was a missed opportunity while there was still time to take “decisive action”, said Sir John.

Following publication of his report examining security at the venue, Paul Hett, the father of Martyn Hett, 29, who died in the bombing, said: “We entrusted the lives of our loved ones to organisations who we believed had a duty of care to protect them.

“This inquiry has rightly found that we were failed by them on every level.

“This atrocity should and could have been prevented, and 22 people would not have lost their lives.”

June Tron, mother of Philip Tron, 32, from Gateshead, killed in the attack, said: “We hope that, as a result of this inquiry, many lessons are learned and that laws are introduced and changes made quickly to ensure people can go to a concert or a big public event in confidence that they have the best possible protection.

“It has become clear that was not the case for Philip, 21 others who also lost their lives, and the hundreds more who were seriously injured or left traumatised by what happened.

“Philip and everybody else in the vicinity of the Arena that night was placed at risk. That is very hard to accept and understand.”

Elkan Abrahamson, from law firm Broudie Jackson Canter, which represents a number of bereaved families, said the report amounted to a “devastating narrative, setting out multiple failures and missed opportunities by a number of organisations”.

He said: “At the start of these proceedings, the prosecuting authorities stated that they would keep the evidence against relevant organisations under review.

“Four years on from the bombing outrage, and with publication of the report, prosecutions should be commenced without further delay.

“Potential charges include corporate manslaughter and offences under the Health and Safety at Work Act 1974.”

Showsec, SMG and BTP all said they would be carefully reviewing Sir John’s findings and recommendations.

Plans to make it a legal requirement for large venues to protect their customers from a terrorist attack were also supported by Sir John.

The Government’s proposed Protect Duty, currently under consultation, builds on Martyn’s Law, called for by Figen Murray, mother of Martyn Hett, and would apply to all spaces to which the public have access.

Hearings at the public inquiry into the circumstances leading up to and surrounding the attack have been continuing in the city since September last year.

A further report will follow on the emergency response and the experience of each of those who died, and finally an analysis of the radicalisation of Abedi and what the intelligence services and counter-terrorism police knew and if they could have prevented the attack.