They came in their thousands, children with their parents, teenagers and adults also in the mix, excited at the prospect of watching a former child star all grown up with grand designs on pop superstardom.
It would not have crossed their minds that carnage lay in wait.
The suicide bomber could have hit a train station, restaurant or busy junction, but he chose former Nickelodeon child star Ariana Grande’s concert at the Manchester Arena on Monday night (early yesterday morning Singapore time).
The killer waited until the end of the concert and as people started streaming out to the foyer, he activated the bomb which some reports say was filled with metal parts.
The choice of location remains unclear, but some estimates said children and teens made up nearly 50 per cent of the audience of 21,000.
The result was devastating – 22 dead and at least 59 injured.
The youngest who died was eight. The first victim to be named was 18-year-old college student Georgina Callander from Lancashire.
The hashtag Missing in Manchester made for difficult reading.
“Everyone pls share this, my little sister Emma was at the Ari concert tonight in #Manchester and she isn’t answering her phone, pls help me,” said one message, posted alongside a picture of a blonde girl with flowers in her hair.
Another Twitter user called Erin:P urged people to help find the user’s sister. “She’s wearing a pink sweatshirt and blue jeans. Her name is Whitney.”
The Islamic State in Iraq and Syria (ISIS) claimed responsibility for the attack.
British Home Secretary Amber Rudd said the Manchester explosion was a “barbaric attack, deliberately targeting some of the most vulnerable in our society”.
Mr Tim Farron, Britain’s Liberal Democrat leader said: “This is a shocking and horrific attack targeting children and young people who were simply enjoying a concert.”
In the hours after the blast, picture montages of smiling faces were being circulated of teens still unaccounted for after the concert.
They carried the hashtag: “#PrayForManchester”.
Speaking to The New Paper, Associate Professor Kumar Ramakrishna, head of policy studies and coordinator of the National Security Studies Programme at the S. Rajaratnam School of International Studies (RSIS), said: “The explosion has shown no mercy to young people and even children. This is similar to ISIS attacks in Syria and Iraq.”
Mr Andrin Raj, South-east Asia regional director for the International Association for Counter-Terrorism and Security Professionals, said ISIS does not discriminate (on the basis of) gender, race or age.
“The attacker himself could have been a young adult who may have got instruction to take out the infidels who are youth,” he said.
British Prime Minister Theresa May said yesterday police and security services knew the identity of the suspected suicide bomber, but the authorities were not ready to announce the name. She also said the attacker had carried out the attack alone.
Ms Cheryl McDonald, who went to the concert with her nine-year-old daughter, told Sky: “I’ve never been so scared in my life. My daughter is very, very shocked”.
Ms McDonald broke down as she described a “devastating” scene, saying the venue was “full of children”.
Ms Paula Robinson, 48, was at the train station next to the arena with her husband when she felt the explosion and saw dozens of teenage girls screaming and running away from the arena.
“We ran out,” she told Reuters. “It was seconds after the explosion. I got the teens to run with me.”
Ms Robinson said she took dozens of teenage girls to a nearby hotel and tweeted her phone number to worried parents telling them to meet her there.
But Centre of Excellence for National Security research fellow Muhammad Faizal Abdul Rahman does not think that the terrorist was intentionally targeting young victims.
Rather, the attacker may have been drawn to Grande’s popularity, which would mean large crowds.
Mr Muhammad Faizal told The New Paper: “To be lethal, suicide bombers need to launch their attack at a crowded place to maximise casualties.”
The Manchester attack is the latest in a series of attacks that have traumatised Europe over the last few years, evoking memories of the attack in 2015 on the Bataclan concert venue in Paris, where gunmen mowed down rock fans.
It is Britain’s deadliest extremist attack in 12 years and comes just two months after a lone assailant left five people dead outside the Houses of Parliament in London.