In the chaos following the deadly attack at the Manchester arena Monday night, witnesses began sharing what they were seeing and hearing almost as quickly as it happened.
The images, videos and statements posted on social media and shared with journalists — at least those that have been verified as real — provide a terrifying timeline of the explosion and its aftermath.
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It began with a still-unverified but seemingly genuine dash-cam video, posted by Twitter user Joe Gregory, who was waiting for his girlfriend outside the arena. The bang inside the venue was barely audible but clear.
The timestamp was off by about an hour, Gregory later explained to various news outlets, because his camera was still set to British Standard Time.
Meanwhile, inside the arena, the explosion was obviously much louder.
“We heard the last record come on and people started streaming out and next thing is a big flash — we didn’t really hear the bang to start off — a big flash,” said one man who was interviewed outside with two young girls.
“And then a whoosh of air. (I) just thought, what the *** was that? And then a smell in the air.”
A wave of panic quickly swept through the venue. Twitter user @hannawwh and others grabbed their phones and began filming the scene.
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More videos, all showing the same things from different angles, were quickly disseminated.
They corroborate witness accounts of people screaming, crying and crowds desperately trying to get to the exits. One clip showed young women tumbling haphazardly over railings in an effort to reach safety.
Another witness, Twitter user @butterywig101, shot a video as she and her friend were making their way up the stairs.
“The staff were telling everyone to keep calm and not run,” she wrote.
At least in her area, people seemed to be following that advice. Numerous witnesses later praised the calm demeanour of arena staff and emergency responders at the scene.
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Around the same time, video filmed in the nearby Victoria transit station showed people streaming away from the arena, as others watched, still confused about what was happening.
Twitter user Zach Bruce witnessed that scene, and later told CBS News that he initially thought the explosion “was part of the show.” Like many concertgoers, Bruce said security inside the venue had been light, and his own bag was not searched as he entered.
WATCH: Witnesses describe chaos around Manchester Arena following deadly explosion
“I was worried, so I just shouted … it was just really scary,” said one young woman after escaping with her father.
Another woman, who accompanied her daughter to the Ariana Grande concert, described “just complete screaming, shouting, just people. Mad chaotic rush to the nearest exit, lots of people crying and wailing and just understandably, just really upsetting for everybody concerned.”
Within a few hours, police had confirmed 22 were dead and dozens more injured.
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In the aftermath of the explosion, witnesses described taxi cabs showing up to offer free rides, while offers of shelter began appearing across social media under the hashtag #RoomForManchester.
At least one witness was praised for her heroism after she rounded up around 50 terrified teens outside the arena and got them to a nearby hotel.
Paula Robinson, 48, told Reuters that by sharing her phone number on Facebook, along with assurances that the teens were being looked after, she hoped to help panicked parents.
“Parents were frantic running about trying to get to their children,” she said.
On Tuesday morning in Manchester, lines began to form outside blood donation centres, as tweeted by Manchester resident Neil R.
So many people showed up that the U.K.’s national blood service had to announce that they had enough blood to treat the injured.
Greater Manchester Police have confirmed the bombing at the arena was a suicide attack and officials believe it was carried out by a lone male suspect. They later confirmed that a second man, 23, was arrested early Tuesday in connection with the deadly explosion.
British Prime Minister Theresa May called it an “appalling” act of terror, and the Queen described the attack as an “act of barbarity.”