Manchester, England(CNN) Aegir had been waiting for the phone call all evening, but it wasn't supposed to sound like this.
Instead of joy and excitement at the end of a long-awaited concert, there was pure panic in his son's voice.
There had been an explosion, Isaac, 15, explained. Then the line went dead.
"It was so terrifying to get that call," Aegir recalls, "They were running out, and I lost the connection with them."
Isaac and his 14-year-old cousin Kara had spent the night watching their idol, Ariana Grande, on stage. The family had come all the way from Iceland for the concert, and had spent months planning their trip.
But an evening that had been filled with music and fun had ended in fear and bloodshed: at least 22 of Grande's fans -- one just eight years old -- dead, and 59 more wounded.
"I thought I was going to die," says Isaac. "I was so scared."
Kara says: "My parents are in Iceland, so my first thought was that I would never see them again."
"We didn't know if there would be another explosion," Isaac explains. "Or if there would be people with guns," adds Kara.
Horrified at the thought of what he might find when he reached the arena, Aegir jumped into a cab and kept calling.
"They said there was blood everywhere. That's when we knew it was serious," Aegir said.
The family counts themselves lucky that Isaac and Kara emerged safe -- albeit traumatized -- from the arena, when so many did not.
"I can't believe it," says Isaac's mom Aslaug. "I'm almost getting more shocked as time goes on and you hear the stories of parents searching for their children -- that could have been us."
And it is this, that the bomber appears to have deliberately targeted a concert with a predominantly young audience, which has horrified so many here.
Hiding her tears behind large sunglasses, Jean Taylor, from Manchester, says she is "devastated, heartbroken," at the thought of "all those young people just going out, having a nice time."
"It's just awful, because ... you're going out to see somebody that you follow, you love the music, everybody is excited for that night, and they'll never be coming back home," Taylor says.
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Large sections of Manchester city center were off limits Tuesday, as police and investigators searched for clues to the deadly attack.
But beyond the cordon, there was plenty of evidence that Mancunians had taken to heart Mayor Andy Burnham's pledge that: "Today it will be business as usual, as far as possible, in our great city."
Indeed, just over 12 hours after the blast hit, the streets were busy with office workers and visitors. People sat at pavement cafes, sharing a bottle of wine with friends, stopped at the hairdressers for a blow dry, or shopped for clothes.
In Albert Square, the city's main public space, workers on their lunchbreak sat in the sun eating sandwiches as TV satellite trucks gathered around them and the memorial to Queen Victoria's husband.
Inside the Victorian Gothic town hall, its corridors lined with statues of the great and the good of Manchester's past, books of condolence had been set up for people to share their thoughts and sympathies.
"You may see the general public going about their daily lives," one contributor had written. "It is not that we don't care ... we do! We are continuing because they cannot win! They want to take away our freedom and we shall not let them."
Even Isaac and Kara and their family were out in the sunshine, exploring the city, determined not to let the events of last night completely color their view of Manchester.
"We're going home tomorrow, but I wanted to walk down here with them," said Aslaug. "It's part of the process of healing, to get out, not to close ourselves in a hotel room.
"I wanted them to feel the compassion -- there's compassion everywhere," she said, as locals laid flowers behind her, in St Ann's Square.
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"It's crazy," says taxi driver Robel Tewolde, originally from Eritrea. "Yesterday, we were talking about football, who's going to win. Today it's a different story."
Manchester is a city known for its friendliness, the sort of kindness that will surround a family visiting from Iceland in a time of adversity and make them honorary Mancunians, even if just for a while.
That empathy was widespread over Monday night and into Tuesday. Soon after the news of the arena attack broke, stories were emerging of small acts of kindness in the face of terrorism: Members of the public offering first aid, drivers providing free rides, local residents giving stranded concert goers a place to stay, restaurants handing out free food to emergency services workers.
Tewolde had taken excited Ariana Grande fans to the show on Monday evening, "then in a few hours, everything changed." He was working nearby when the blast rocked the arena.
"I didn't know what had happened, but then I saw a flood of people. I tried to help them, direct them to a safe place -- a petrol station where they could meet up with their families."
Artist Rachel Harrington struggled to find something she could do to help.
"I don't have a car, I don't have a bed to offer anybody. I was going to give blood, but they say they don't need any more, but I can do this," she says, gesturing at her latest artwork: the words of Mayor Burnham, "We are grieving today, but we are strong," chalked onto the pavement of Albert Square, in the shadow of the town hall.
Harrington says she hopes the impromptu artwork will show the victims, survivors and families that "we're all there for them, we're all together and we're going to get through this."
A minister, Daniel Valentine, was part of a team supporting visitors to St Ann's Church in the city center, which offered people a "space to comprehend what's happened." He said as soon as the church opened on Tuesday morning, people stopped by to offer drinks and refreshments.
"Even in the depths of the most horrible, horrible assault, the people of Manchester are showing how wonderful humanity can be," Valentine added.
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Manchester is a proud city: Proud of its industrial heritage, its soccer prowess (many signs are using the names of its rival teams City and United to make a point), its music scene, and proud too, that it has weathered tough times -- surviving previous terror attacks -- and has bounced back, bigger and bolder than before.
Tony "Longfella" Walsh voiced this pride and defiance -- to massive cheers, and a fair few sobs -- at the vigil in Albert Square on Tuesday evening, with his poem "This is the place."
He reminded Mancunians of their history -- and their destiny: "To survive and to thrive. And to work and to build. And to connect and create. They'll never defeat the dreamers and schemers who teem through these streets."
"There's hard times again in these streets of our city. But we won't take defeat, and we don't want your pity," Walsh insisted. "Because this is the place where we stand strong together.
"Because this is the place, in our hearts and our homes. Because this is the place. It's a part of our bones."
Manchester is also known for its diversity, with large Muslim and Jewish communities, and a sizeable LGBT population.
The crowd at the vigil reflected this, with Mancunians of all ages, faiths and genders present.
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Councillor Eddie Newton, Lord Mayor of Manchester, told those who gathered in the square that the people of Manchester would "defy the terrorists, by all our diverse communities working together."
His words were echoed by many of those listening in the square. "We are together," said Charanjit Singh Heera, from Manchester's Sikh community. "We cannot be broken with this type of barbaric, heinous act. Whoever did this should be ashamed, but they will not break up the city."
"They are few," the Bishop of Manchester, David Walker, told the crowd of thousands. "We are many. We are Manchester."