A senior officer accepted police failed to have a contingency plan in place at Manchester Arena in the event of a major incident.
Chief Supt Allan Gregory, of British Transport Police, gave evidence at the public inquiry into the Manchester Arena terror attack.
Salman Abedi detonated a bomb in May 2017 at the end of an Ariana Grande concert, killing 22 people and injuring hundreds.
The hearing was told the arena was the UK’s only entertainment venue of such scale under the control of the transport police and Mr Gregory said there was no contingency plan in case of a major emergency.
When asked if this was an omission, he said: "In light of that awful event in May 2017, clearly that is a conclusion I would have to agree with."
He told the hearing that emergency services had failed to work together and said the local police force had failed to liaise with transport police.
Mr Gregory said he regretted not communicating with commanders of Greater Manchester Fire and Rescue Service and Greater Manchester Police.
"I should have been more diligent around reaching out and having conversations about what they understood," he said.
British Transport Police Chief Insp Tony Lodge told the inquiry that nearly an hour after the attack he was still trying to establish who had primary control.
Gold commander Robin Smith said better communication between emergency services was needed.
"Half the challenge is knowing who to ring and you are trying to ring the busiest people in the organisation," he said.
"The key thing is who you need to talk to."
Mr Smith suggested a WhatsApp group to aid communication.
"I think we could do that and I do not think it would be difficult. We can do better if we can communicate.
"That is what I would have enjoyed on the night."
During the inquiry, the emergency services were criticised for their slow response and relatives and survivors condemned delays in the treatment of victims and the evacuation.
The Manchester Arena Inquiry, set up by UK Home Secretary Priti Patel in October, is examining the circumstances of the attack and whether any opportunities to prevent it were missed.
Suicide bomber Abedi, 22, died as he detonated a rucksack bomb in a foyer.
His younger brother, Hashem Abedi, was convicted last year on 22 counts of murder, one of attempted murder and one of conspiracy to cause an explosion.
He was sentenced to jail for a minimum of 55 years.
Results
Light Flyweight (49kg): Mirzakhmedov Nodirjon (UZB) beat Daniyal Sabit (KAZ) by points 5-0.
Flyweight (52kg): Zoirov Shakhobidin (UZB) beat Amit Panghol (IND) 3-2.
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Welterweight (69kg): Bobo-Usmon Baturov (UZB) beat Ablaikhan Zhussupov (KAZ) RSC round-1.
Middleweight (75kg): Jafarov Saidjamshid (UZB) beat Abilkhan Amankul (KAZ) 4-1.
Light Heavyweight (81kg): Ruzmetov Dilshodbek (UZB) beat Meysam Gheshlaghi (IRI) 3-2.
Heavyweight (91kg): Sanjeet (IND) beat Vassiliy Levit (KAZ) 4-1.
Super Heavyweight ( 91kg): Jalolov Bakhodir (UZB) beat Kamshibek Kunkabayev (KAZ) 5-0.
Our legal advisor
Ahmad El Sayed is Senior Associate at Charles Russell Speechlys, a law firm headquartered in London with offices in the UK, Europe, the Middle East and Hong Kong.
Experience: Commercial litigator who has assisted clients with overseas judgments before UAE courts. His specialties are cases related to banking, real estate, shareholder disputes, company liquidations and criminal matters as well as employment related litigation.
Education: Sagesse University, Beirut, Lebanon, in 2005.
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THE BIO
Born: Mukalla, Yemen, 1979
Education: UAE University, Al Ain
Family: Married with two daughters: Asayel, 7, and Sara, 6
Favourite piece of music: Horse Dance by Naseer Shamma
Favourite book: Science and geology
Favourite place to travel to: Washington DC
Best advice you’ve ever been given: If you have a dream, you have to believe it, then you will see it.
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