Manchester suicide bomber Salman Abedi carried a rucksack packed with a "massive number" of small metal objects which "flew through the air at high velocity in all directions" when detonated, a court has heard.
The inquests into the deaths of the 22 victims of the Manchester Arena terror attack were told the improvised explosive device contained in the bag he was carrying on his back appeared to be "designed to kill and maim indiscriminately the largest number of innocent people".
A map shown during a hearing at Manchester Civil Justice Centre suggested the nearest victim, 14-year-old Cheshire schoolgirl Nell Jones - who was at her first pop concert - was just five yards from Abedi, while the furthest was school receptionist Jane Tweddle, 51, some 20 metres away.
Senior coroner for Manchester Nigel Meadows opened the inquests as brief summaries to the background circumstances of each of the fatalities was outlined.
None of the families of the deceased attended the hearing, which lasted just short of a hour and was preceded by a minute's silence for the victims, bereaved, injured and those affected by the bombing on May 22 and also the London Bridge atrocity.
A photograph of each of the victims was shown on a large screen along with their dates of birth and then the map, which pinpointed Abedi, 22, in the middle of the large foyer area of the indoor arena and where each person was when he detonated the device.
Nineteen of the concert-goers died at the scene while three - including the youngest victim, eight-year-old Saffie Roussos - were rushed to hospital but pronounced dead shortly afterwards, the inquests were told.
Detective Superintendent Jonathan Chadwick, the senior identification manager for the incident, told the hearing: "At 10.31pm on May 22 2017 a man subsequently identified as Salman Ramadan Abedi detonated an improvised explosive device in the Manchester Arena complex in Manchester city centre.
"The device had been contained in a rucksack he was carrying on his back.
"It was packed with a massive number of small metal objects which on detonation flew through the air at high velocity in all directions.
"It appears it was designed to kill and maim indiscriminately the largest number of innocent people."
He added that at the time of the explosion, the foyer near Victoria Station was full of people making their way out following the performance by Ariana Grande.
A total of 220 people received medical treatment as a result of the blast, said Mr Chadwick.
A number of those have life-changing injuries and a small number remain critically ill.
Updating the investigation by the North West Counter Terrorism Unit, he said 21 people had been arrested in connection with the attack, of whom 18 have been released and three remain in custody.
He said 32 addresses had been searched and 10 were still under police control.
Each of the 22 inquests was opened and adjourned until November 24 for pre-inquest review hearings.
The court heard the bodies of the victims were all later taken to the mortuary at Royal Oldham Hospital where post-mortem examinations took place to establish the causes of death.
Identification then took place through dental records and DNA tests, together with analysing items recovered at the scene such as mobile phones, jewellery, watches and clothing.
Concluding the inquests Mr Meadows, who was assisted by Professor Jennifer Leeming, coroner for West Manchester, and Joanne Kearsley, coroner for North Manchester, said: "I must pay tribute to the truly unbelievable dignity and strength of spirit that all the bereaved families have demonstrated in the face of such overwhelming grief."
He acknowledged the work done "behind the scenes" by people who responded to the attack, including members of the public who were there, the emergency services, staff at the arena and doctors and nurses - "too many to list" - who had treated those injured in the incident.
He also praised the "tremendous" work done by Greater Manchester Police crime scene management officers, police family liaison officers, mortuary staff and forensic pathologists.
He said: "The response to this tragic incident has been a complete and total team effort from all."
An inquest into Abedi's death will be opened at a later date.
A sea of flowers left at St Ann's Square in the city in memory of those killed and injured in the attack will be removed on Friday, with access to the square restricted after 6pm.