Manchester Arena Terrorist Attack 2017

United Kingdom

Integrated Summary

By Anthony Gledhill | July 2025

.

Manchester Arena Inquiry Reports

This summary has been compiled directly from the findings, conclusions and recommendations contained within the Manchester Arena Inquiry reports: Volume 1: Security for the Arena (2021), Volume 2: Emergency Response (2022) and Volume 3: Radicalisation and Preventability (2023).

The article summarises the main findings presented by The Hon Sir John Saunders and the Manchester Arena Inquiry team. Its purpose is to provide clear, practical learning that can be used to improve protective security and counter terrorism capability within the private sector.

This summary uses approximately 1500 words to identify and deliver key points from the reports. The author of this summary has added some comments in red next to some of the lessons learned points.

.

Introduction

The Manchester Arena Inquiry, chaired by The Hon Sir John Saunders, was launched to examine the circumstances surrounding the terrorist bombing at Manchester Arena on 22 May 2017, during an Ariana Grande concert. The bombing, carried out by Salman Abedi (SA), was the deadliest terrorist attack in the UK since the 7/7 bombings in 2005.

• Volume 1 focused on the security arrangements at the venue, highlighting missed opportunities and failings by SMG (the operator), Showsec (the security contractor), and British Transport Police (BTP).
• Volume 2 analysed the emergency response, scrutinising the effectiveness and readiness of Greater Manchester Police (GMP), Greater Manchester Fire and Rescue Service (GMFRS), North West Ambulance Service (NWAS), and other responders. It detailed how the response was compromised by poor communication, lack of coordination, and inadequate preparedness.
• Volume 3 addressed the radicalisation process, planning, and whether the attack could have been prevented, examining the actions of the Security Service (MI5) and Counter Terrorism Policing.

Collectively, the Inquiry’s purpose was to hold organisations accountable, to provide answers to the bereaved, and to shape robust measures to prevent similar atrocities.

.

Casualties

Twenty-two innocent people lost their lives; they were children, teenagers, parents, and friends who had gathered to celebrate music. Hundreds more suffered severe physical injuries and enduring psychological trauma. Their names, as memorialised across all three volumes, are central to the Inquiry’s work.

.

Timeline

22 May 2017

Evening. Over 14,000 people attended the Ariana Grande concert.

20:30–22:30. SA carried out hostile reconnaissance, exploiting CCTV blind spots and security gaps.

22:31. SA detonated the device in the City Room as crowds were exiting. Twenty-two were killed instantly or died soon after from catastrophic injuries. Hundreds were injured:

• Post-Attack. The emergency response was immediate in parts but marred by severe delays, miscommunication, and a lack of joint command structure.

• Investigations. The public inquiry was formally established in October 2019. Reports were published progressively: Volume 1 in June 2021, Volume 2 in November 2022, and Volume 3 in March 2023.

.

Investigating Bodies

• Chair. The Hon Sir John Saunders, appointed as Coroner and Inquiry Chair.
• Volumes Produced By. Manchester Arena Inquiry Team under statutory powers of the Inquiries Act 2005.
• Oversight. Assisted by Counsel to the Inquiry, survivors, bereaved families, security experts, and the wider public through hearings.

.

Attacker Planning Before the Attack

Volume 3 detailed SA’s radicalisation trajectory, influenced heavily by his family’s connections to violent extremism, travel to Libya for military training, and exposure to ISIS ideology. Despite being known to the Security Service, SA’s threat level was downgraded before his final travel back to the UK.

From 2010 to 2017, there were multiple missed opportunities:

• Intelligence identified him as a subject of interest but he was not under active investigation.
• Indicators of extremist behaviour were overlooked by schools, mosques, and Prevent partners.
• He travelled to Libya and returned with clear indicators of militant preparation, including communication with known extremists.

In the days before the attack, SA procured and assembled bomb components in rented premises, made test detonations, and conducted reconnaissance of the Arena’s vulnerabilities.

.

Actions Taken by the Attacker

On the night, SA:

• Arrived at the Victoria Exchange Complex at 20:30.
• Moved repeatedly in and out of the City Room, exploiting known CCTV blind spots and weak security patrols.
• Remained undetected by security and police despite suspicious behaviour flagged by members of the public.
• At 22:31, detonated his device among families collecting children, causing mass casualties in seconds.

.

Visitor & Staff Actions During the Attack

Accounts from Volume 1 and 2 show that:

• Some security staff noted his suspicious behaviour but lacked the confidence, experience, or supervision to act decisively.
• One member of the public raised concerns about SA to a security supervisor, but the follow-up was inadequate.
• Once the explosion occurred, concertgoers, venue staff, and off-duty police officers provided immediate first aid.
• Members of the public used makeshift stretchers and improvised lifesaving efforts in the chaos.

.

Preplanned Security Measures at the Facility

The Inquiry found the Arena’s security framework was fundamentally flawed:

• Risk assessments by SMG and Showsec failed to adequately address the credible threat of terrorism, despite the high threat level.
• The perimeter security and bag checks were inconsistent; the City Room, a prime gathering point, was poorly protected.
• CCTV blind spots, including the mezzanine, provided the attacker with a place to hide in plain sight.
• The reliance on part-time, inadequately trained security staff and limited counter terrorism expertise severely undermined threat detection.
• The British Transport Police, responsible for policing the area, did not maintain a visible, deterrent presence throughout.

.

Security Staff Actions Before and During the Attack

The Inquiry’s Volume 1 conclusions were stark:

• Missed opportunities by Showsec staff and BTP patrols were directly linked to the failure to disrupt SA.
• A lack of clear command, supervision, and communication meant staff were ill-equipped to handle potential threats.
• There was an over-reliance on generic industry practice rather than tailored counter terrorism security measures.

.

Emergency Response Effectiveness

Volume 2 revealed significant failures:

• There was no coordinated command structure in the early critical minutes.

• Greater Manchester Police did not activate their Major Incident Plan correctly; GM Fire & Rescue Service failed to attend the scene promptly due to confusion over rendezvous points. Comment: Post-incident discussion frequently focused on the actions and decisions of individuals rather than the effectiveness of the system itself. Yet the procedures, command arrangements, and interoperability processes had been developed, taught, and exercised for many years before the attack. This raises a fundamental question for security and emergency management practitioners: if experienced personnel do not implement a system effectively under the pressures of a real major incident, is the primary failure with the people, the system, or the system’s ability to prepare people to perform under operational conditions? A robust system should be capable of supporting effective decision-making under stress, uncertainty, and cognitive overload, rather than relying on flawless individual performance.

• North West Ambulance Service deployed paramedics but did not send enough into the blast area; the use of stretchers was inadequate.

• The Care Gap the period between the incident and effective medical intervention was widened due to these failures. Comment: The so called care gap is a smoke screen, the long standing term within the industry is The Emergency Services Response Gap – its the crucial period organisations and people must act to save lives and lower the criticality under their own direction. That gap must be treated as the priority period by any organisation for mitigation.

Despite these systemic problems, individual acts of heroism by first responders, arena staff, and bystanders undoubtedly saved lives.

.

Lessons Learned and Recommendations

Across the three volumes, the Inquiry’s key recommendations included:

• Implementation of a statutory Protect Duty to ensure venues assess and mitigate terrorist threats proportionately. Current Position: This recommendation subsequently developed into the Terrorism (Protection of Premises) Act 2025, commonly known as Martyn’s Law. The Act received Royal Assent on 3 April 2025. Its main requirements are not yet in force, although statutory guidance has now been published to support organisations preparing for implementation.

• Improved training and accreditation for security staff, including behavioural detection. Comment: This goal is unlikely to be achieved while SIA courses remain accepted as the default standard. Meaningful progress will require significant reform in the SIA’s leadership; at present, it is a case of the blind leading the blind.

• Enhancements to CCTV systems to eliminate blind spots. Comment: As long as the SIA CCTV Operator licence is seen as the standard of excellence, eliminating blind spots will have limited value. Most operators still lack training in situational awareness and behavioural detection, and we are eight years on from the attack. The reality is that the SIA badge remains the default benchmark, despite these critical gaps.

• Strengthened multi-agency emergency preparedness with clear command structures and joint exercises. Comment: This will remain limited in impact until the problem of theory blindness within the emergency services is addressed and groupthink is actively challenged. Without tackling these issues, the same ineffective systems used during past incidents will persist in future responses.

• Reforms to MI5 and Counter Terrorism Policing to improve handling of low-level threats, review processes, and information sharing.

• Better integration of the Prevent strategy within communities, educational institutions, and local policing. Comment: Serious failings with the Prevent Strategy continue to emerge in connection with recent attacks. It is clear that lessons have not been fully learned, even eight years after the Arena Attack.

Comment: For more than two decades, the SIA’s focus on volume over quality and competence has seriously undermined the capability and professionalism of UK security staff. It is often described as a badging factory for good reason, producing an oversupply of low-value, poorly skilled personnel to feed large organisations who have created barriers and a race to the bottom on pricing.

.

What Should Organisations Learn From the Manchester Arena Inquiry?

The findings and recommendations above provide important lessons, but their real value comes from considering whether similar weaknesses could exist within other organisations today.

Policies and procedures existed. Training had taken place. Security arrangements were in place. Experienced organisations and people were involved. Yet opportunities were missed, information was not always acted upon effectively and, following the attack, communication, coordination and decision making did not always work as intended.

There is an important lesson here.

Having a policy, procedure or training record does not necessarily mean an organisation has the capability to make it work when it matters.

For security managers, protective security and counter terrorism practitioners, the Inquiry provides an opportunity to look at their own organisation and ask some difficult but practical questions:

• Can staff recognise when something is wrong and know what to do about it?
• Can observations and concerns be communicated quickly to someone capable of making a decision?
• Do managers understand the threats, vulnerabilities and risks affecting their organisation, rather than simply having them recorded in documents?
• Can security, management and other stakeholders work together when information is incomplete and time is limited?
• Are people capable of making credible decisions under pressure without waiting unnecessarily for somebody else to tell them what to do?
• Have emergency and crisis arrangements actually been tested against realistic circumstances, including confusion, conflicting information and human behaviour?

The purpose is not to ask whether another Manchester Arena attack could happen in exactly the same way. Threats, tactics, locations and circumstances change.

The better question is whether the underlying weaknesses identified by the Inquiry could appear within your own organisation in a different form.

That is where the lessons from Manchester become useful.

Documents provide structure. Training provides knowledge. Neither guarantees capability.

The real test is whether people can recognise what is happening, understand its significance, make sound decisions, communicate effectively and act when it matters.

Conclusion

The Manchester Arena Inquiry provides a detailed account of the attack, the events surrounding it and the opportunities that were missed. Its value, however, extends far beyond understanding what happened in Manchester on 22 May 2017.

For organisations responsible for protecting people, the lasting lesson is that protective security cannot rely on policies, procedures, training or physical measures alone. Each has a purpose, but they must work together and, ultimately, depend on people recognising what is happening, communicating concerns, making credible decisions and taking appropriate action.

The Inquiry also demonstrates why lessons from previous incidents need to be understood and applied, not simply recorded. Threats and circumstances will change, but weaknesses in observation, communication, decision making, coordination and preparedness can appear again in different forms.

Organisations should therefore use the Manchester Arena Inquiry as more than a reference document. It provides an opportunity to examine their own arrangements, identify where assumptions may exist and determine whether the capability described on paper would actually work under pressure.

That is where lessons learned become lessons applied.

About the Author:

Anthony Gledhill is the founder of Mildot Group and a protective security and counter terrorism practitioner with more than 40 years of military and private sector experience.

Following 22 years in the British Army, including operational counter terrorism, he moved into private sector security in 2007. His experience spans operational security, corporate leadership and consultancy in the UK, Middle East and other complex environments affected by terrorism, insurgency and organised crime.

His work focuses on turning protective security and counter terrorism requirements, guidance and lessons learned into practical capability.

.

Developing the Capabilities Identified by the Inquiry

The Manchester Arena Inquiry identified weaknesses across protective security, observation, communication, decision making, coordination and emergency response. Understanding those lessons is important. Developing the capability to apply them is what makes them useful.

Mildot Group provides practitioner focused programmes that develop several of the capabilities discussed throughout this article.

Private Sector Counter Terrorism Practitioner

Develop the judgement and practical capability to understand threats, vulnerabilities and risk, interpret requirements and guidance, assess what is reasonable and practicable, and turn protective security knowledge into action.

Situational Awareness & Behavioural Observation

Develop the ability to understand an environment, recognise when something moves outside the expected baseline, identify anomalies and make better informed decisions about what requires attention or action.

Crisis Management & Business Continuity for Security & Counter Terrorism Practitioners

Develop the capability to make decisions, communicate, coordinate and maintain an effective response when an incident develops, information is incomplete and normal operating conditions begin to break down.

Each programme is designed around the same principle reflected throughout this article: knowledge has value, but capability is demonstrated by what people can actually do with it.

Article References

Manchester Arena Inquiry (2021) Volume 1: Security for the Arena. Report of the Public Inquiry into the Attack on Manchester Arena on 22nd May 2017. Chairman: The Hon Sir John Saunders. Presented to Parliament pursuant to section 26 of the Inquiries Act 2005.

Manchester Arena Inquiry (2022) Volume 2: Emergency Response. Report of the Public Inquiry into the Attack on Manchester Arena on 22nd May 2017. Chairman: The Hon Sir John Saunders. Presented to Parliament pursuant to section 26 of the Inquiries Act 2005.

Manchester Arena Inquiry (2023) Volume 3: Radicalisation and Preventability. Report of the Public Inquiry into the Attack on Manchester Arena on 22nd May 2017. Chairman: The Hon Sir John Saunders. Presented to Parliament pursuant to section 26 of the Inquiries Act 2005.

Copyright & Source Statement

This report summary is an independent assessment compiled using material from the Manchester Arena Inquiry reports: Volume 1 (Security for the Arena), Volume 2 (Emergency Response), and Volume 3 (Radicalisation and Preventability), chaired by The Hon Sir John Saunders. The original reports are © Crown copyright and licensed under the Open Government Licence v3.0.

The text has been adapted for succinctness and clarity.

You are free to use this content under the terms of the Open Government Licence. To view this licence, visit: www.nationalarchives.gov.uk/doc/open-government-licence/version/3.

Source: Manchester Arena Inquiry Reports (2021–2023), available at www.manchesterarenainquiry.org.uk
Any errors of interpretation are the responsibility of the publisher.

.

Corporate Accounts Brochure

Discover how Mildot Group can help your organisation develop stronger judgement, practical capability and more confident decision making.

Useful Links:

.