People lay tributes at a vigil for those who died during the Manchester terrorist attack. (Andy Rain/European Pressphoto Agency)

It was supposed to be one of the best nights of their life: a concert featuring the American singer Ariana Grande and thousands of like-minded fans.

But for at least 22 people attending the concert in Manchester on Monday, it was the last night of their lives.

They were killed in an apparent suicide attack after the event ended. Authorities said at least 59 people were injured.

Saffie Rose Roussos, an 8-year-old, was among those killed as she was leaving the packed concert at Manchester Arena.

Pictures of the smiling youngster were featured in many British news outlets.

Saffie Rose Roussos, an 8-year-old, was among those killed as she was leaving the packed concert at Manchester Arena. (Press Association via Associated Press)

Authorities haven’t officially released the names of the victims, but three have been identified locally.

Saffie is the youngest victim to have been identified. The elementary school student was at the concert with her mother, Lisa, and older sister Ashlee, who are reportedly being treated for shrapnel injuries in separate hospitals.

She was “simply a beautiful little girl in every aspect of the word,” Chris Upton, the principal of Tarleton Community Primary School, said in a statement.

Saffie was “loved by everyone and her warmth and kindness will be remembered fondly,” he said, adding that “Saffie was quiet and unassuming with a creative flair.”

According to the Daily Telegraph, her parents are thought to run a fish-and-chip shop.

The attacker appeared intent on causing maximum casualties by detonating his device at the moment when concertgoers — families, teenagers and tweens — were streaming out of Manchester Arena. The venue is one of Europe’s largest, with a seating capacity of 21,000.

John Atkinson, a man in his 20s from Radcliffe, a town about 10 miles north of Manchester, was named as one of the fatalities by friends on social media and in the British news media.

Facebook user Nayomie Louize updated her profile picture to one of her and Atkinson and invited people to join her at a gathering on Tuesday evening in honor of her late friend.

“Come with balloons, lanterns, candles to be set off in loving memory of our beautiful beloved friend and family member,” she wrote.

Friends also paid tribute on a crowdfunding page set up to help with Atkinson’s funeral costs.

Natalie Dalton, a contributor, wrote on the page: “Absolutely devastated. What a great caring gentleman you was. Fly high mate. You will be missed by many xxxx”

An undated photo from the Instagram account of Georgina Callander. Callander was an 18-year-old college student studying health and social care. (Reuters)

The first named fatality in the attack was Georgina “Gina” Callander, an 18-year-old college student studying health and social care.

The day before she died, she responded to a post from Grande, tweeting, “SO EXCITED TO SEE U TOMORROW.”

Callander was a massive Grande fan. She had met the pop singer in 2015 and posted a photo of the two of them on social media. At the time, she wrote, “I can’t believe this happened.”

Callander’s former school posted a picture of her on its website and described her as popular and active within the school.

“Georgina was a lovely young student who was very popular with her peers and the staff and always made the most of the opportunities she had at the school,” said the Bishop Rawstorne Church of England Academy in Croston, about 30 miles northwest of Manchester.

Her friend Shelby Wharton, 17, described her as “kind and loving.”

“We were all praying for her to be found safely. Then we were told she had passed away,” Shelby told London’s Evening Standard newspaper.

Several friends posted pictures of Callander online and paid tribute to the teenager.

Sophie Jauregui tweeted: “To my beautiful best friend I hope you rest in peace my darling. I love you so much and will always miss you.”

Meanwhile, parents and friends on Tuesday were still frantically issuing missing-person pleas. Many of those who remain unaccounted for are teenagers.