Two PCSOs missed suicide bomber Salman Abedi by 59 seconds when they checked toilets at Victoria railway station on the night he carried out his terror attack.
Abedi, weighed down by the heavy rucksack carrying his bomb, had 'positioned himself' in the loos on the station concourse, leaving at 8.48pm.
CCTV images showed PCSOs Lewis Brown and Jon Morrey conducting a routine check of the toilets less than a minute after Abedi had exited, the public inquiry into the atrocity has heard.
Footage showed Abedi struggling under the weight of his rucksack, which was packed with shrapnel and TATP explosives.
Later that night he made his way to the adjacent Arena and detonated a huge bomb in his rucksack as people were leaving an Ariana Grande concert, killing himself and 22 innocents in May 2017.
The two PCSOs, a third PCSO Mark Renshaw, and constable Jessica Bullough, were all together at the 'war memorial' exit of the railway station at the moment the bomb went off.
As the 14th day of the public inquiry got underway today, Detective Chief Inspector Sam Pickering outlined a timeline of events, including the 'hostile reconnaissance' carried out by Abedi at the Arena on May 18, May 21 and during the early evening of May 22, the day of the attack.
CCTV footage showed Abedi had chatted to Showsec stewards during the early evening of May 22, when he didn't yet have his rucksack. He is seen walking by the same stewards later that night, this time wearing the rucksack.
The inquiry has previously heard that that Abedi made his final approach from the Metrolink platform to the Arena, via the Victoria railway station concourse, during a 22-minute period when no BTP officer was patrolling the station.
PC Bullough and PCSO Renshaw left the station at 7.27pm to buy food and returrned 45 minutes later, at 8.12pm, to eat in a room at the station.
The officers resumed their patrols at 9.37pm some two hours and ten minutes after they had left to buy food, the inquiry has been told.
PCSOs Morrey and Brown are said to have started their hour-long break from 9.15pm, meaning no BTP officers were patrolling the station for 22 minutes until PC Bullough and PCSO Renshaw resumed their duties.
CCTV shown to the inquiry on Thursday showed the officers in or near the City Room as excited concert-goers made their way into the gig.
Salman Abedi 'positioned himself' in the station concourse toilets, leaving at 20.48, DCI Pickering confirmed.
The two PCSOs went to check the toilet but missed the already-departed Abedi by just 59 seconds, the inquiry heard.
An image timed at 10.31pm shows the four British Transport Police officers stationed at the war memorial entrance - the minute the bomb went off.
The inquiry heard the real timing of that image would be discussed further during up-coming evidence to consider whether it was before or after the bombing.
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Sir John Saunders, a retired High Court judge, is leading the inquiry which is examining events before, during and after the attack, including the radicalisation of Manchester-born Abedi, to see if lessons can be learned.
It resumes on Monday and is expected to continue into the new year.