A public inquiry that will examine alleged failures to prevent the Manchester Arena bombing will begin today.
Salman Abedi killed 22 people and injured almost 1,000 more on 22 May 2017, when he blew himself up as Ariana Grande fans left a concert at the stadium.
Isis claimed responsibility for the blast, which was the deadliest of four lethal terror attacks that struck the UK that year.
A review of MI5 intelligence later revealed that security services drew the “wrong conclusions” from two key pieces of information in the run-up to the bombing.
Abedi had already been put under active investigation over terrorist links twice, but no alert was triggered when he travelled back to the UK from Libya just four days before the attack.
Families of the victims and survivors were also critical of the emergency response to the blast, which was affected by safety procedures and communication difficulties.
In total, 22 victims were killed, 264 people were injured and 710 survivors have reported suffering from psychological trauma.
The inquiry is expected to hear evidence until next spring, including on the preparations for the attack and Abedi’s radicalisation.
It will hear evidence on “what was or what ought to have been known about the threat posed by Salman Abedi” and the actions of the security services, although some information may be restricted to closed sessions following applications by the Home Office and police.
The treatment of each deceased victim will also be examined, as well as the “adequacy” of the wider emergency response.
The inquiry was delayed by the prosecution of the bomber’s brother, Hashem Abedi, who was jailed for life last month for his role in the plot.
Inquests were originally due to be held into the 22 victims’ deaths, but Priti Patel made the decision to mount a public inquiry last October following recommendations by chair Sir John Saunders.
Sir John will open proceedings with a minute’s silence for the victims on Monday, before the main issues are summarised and commemorative hearings are held for families to pay tribute to loved ones.
Evidence is not expected to begin until 1 October, following opening statements by core participants including bereaved families and Greater Manchester Police.
A spokesperson for the Manchester Arena Inquiry said: “The inquiry will investigate the circumstances of how the 22 people killed in the Arena attack died.
“It will also examine evidence about the arena complex and security arrangements; the planning and preparation for the attack, the events of 22 to 23 May 2017, the emergency response, the detonation and its effect, the experience of each of the 22 deceased, the background and radicalisation of Abedi and the preventability of the attack.”
Because of the coronavirus pandemic, members of the public are not currently permitted to attend inquiry hearings at Manchester Magistrates’ Court but can watch a live video feed and read transcripts.