U.K. Prime Minister Theresa May called the bombing a "sickening attack" that targeted children and young people "who should have been enjoying one of the most memorable nights of their lives."
"We struggle to comprehend the warped and twisted mind that sees a room packed with young children not as a scene to cherished but as an opportunity for carnage," May said Tuesday.
According to the Greater Manchester Health and Social Care, a total of 119 people were taken by ambulance or went to a hospital following Monday night's attack at Manchester Arena. Officials said 64 were being treated as of Wednesday and 20 of them remained in critical condition across Greater Manchester.
At least 12 children under the age of 16 were seriously injured, officials said. An 8-year-old girl who died from her injuries is the youngest known victim in the attack.
Saffie Rose Roussos
Among the dead is Saffie Rose Roussos, described by her teacher as a "beautiful little girl."
Saffie had become separated from her mother and sister during the attack.
Chris Upton, the headteacher at the Tarleton Community Primary School, where Saffie was a student, released a statement calling the girl's death a "tremendous shock."
"I would like to send our deepest condolences to all of her family and friends," Upton said. "The thought that anyone could go out to a concert and not come home is heartbreaking. Saffie was simply a beautiful little girl in every aspect of the word. She was loved by everyone and her warmth and kindness will be remembered fondly. Saffie was quiet and unassuming with a creative flair."
Upton said the school will be calling in specialists to help students and staff cope with Saffie's death.
Runshaw College confirmed that the 18-year-old college student was among the victims.
"It is with enormous sadness that it appears that one of the people who lost their lives in Monday’s Manchester attack was one of our students here at Runshaw College," school officials said in a statement posted on Facebook. "Georgina Callander was a former Bishop Rawstorne pupil studying with us on the second year of her Health and Social Care course. Our deepest sympathies, thoughts and prayers go out to all of Georgina’s friends, family, and all of those affected by this loss."
"RIP my darling precious gorgeous girl Olivia Campbell taken far far to soon go sing with the angels and keep smiling mummy loves you so much," Olivia's mother, Charlotte Campbell, wrote on Facebook.
Prior to learning that her 15-year-old daughter had been killed in the attack, the teen's mother pleaded for the public to help her locate her daughter, telling the BBC, "I’m worried sick. If anybody has seen her please contact the police. Contact somebody let her know you’ve seen her. Even if you think you’ve seen her just let the police know ... We’ve not slept. We’ve got family out looking for her. Please, please somebody must have seen her at some point. Just let me know you’ve seen her. Let the police know, let anybody know you’ve seen her please."
The 43-year-old mother and grandmother was also among those killed. One of her daughters, Lauren Ashleigh Lees, described her as "a very elegant person" and "an amazing" mother, grandmother and wife who was "absolutely adored" by everyone around her.
"She cared so much for everybody and did anything for them," Lauren Ashleigh Lees said in a statement. "We will pull together as a family and help each other through the darkness."
The ninth-grader was confirmed to have died in the attacks by her school, Holmes Chapel Comprehensive and Sixth Form. The girl's family had searched for her after she attended the concert, but the teen died at the scene, according to her school's headteacher Denis Oliver.
"We are all devastated by the loss and as a school community we must now come to terms with what has happened," Oliver said in a statement.
The school plans on bringing in professional support to help teachers and students grieve.
Nell's form tutor David Wheeler called the teen "always smiling."
“Nell was a very popular girl, always smiling, always positive," Wheeler said in the statement. "Her tutor group have been together since the transition from primary school. It feels like they have lost a sister not a classmate”
Another student at the school, Freya Lewis, was hospitalized after the attack. Her father told the school that the teen is recovering after having been in surgery for over 10 hours.
Hett's employer, Rumpus PR, confirmed his death in a statement, calling Hett "larger than life, colourful and charismatic."
Paul Evans, managing director of Rumpus PR, said Hett was a "talented writer, creative thinker and social media expert."
"Words really can’t express how much he will be missed by colleagues and clients alike," Evans said in a statement. "Martyn loved life and I hope his lasting legacy is that people -- in these dreadful times -- choose to live their lives with joy not hate, just like he did."
Chloe Rutherford and Liam Curry
In a statement, the teens' families said, "They were perfect in every way for each other and were meant to be."
"They wanted to be together forever and now they are."
"Jane was a well-loved member of staff and our thoughts are with her friends and family at this terrible time," Jane Bailey, principal of South Shore Academy, said in a statement about the receptionist. "We have received numerous messages of condolences from parents, students, community members and colleagues across Blackpool, for which we are very grateful. All of them say the same things about our lovely Jane ... bubbly, kind, welcoming, funny, generous ... the list goes on."
Allerton High School in Leeds confirmed that student Leczkowski was killed as well. "Sorrell was a delightful member of the school community," read a statement from the school. "She enjoyed her studies, had a lovely group of friends and was a real asset to Allerton High School."
Her family wrote the teen had gone with her mother and grandmother to the concert to pick up family members.
"I am absolutely heartbroken to confirm that my granddaughter was killed in the terror attack that claimed so many innocent lives," her grandfather wrote. "Sorrell was only 14, but she was our rock, she kept us grounded."
He wrote the teen wanted to attend architecture school at Columbia University in New York.
MacLeod's family said they were devastated by the teen's death.
"Eilidh was vivacious and full of fun. She loved all music whether it was listening to Ariana or playing the bagpipes with her pipe band," the girl's family wrote in a statement released by police.
Fawell's son said that his mother "touched the lives of so many."
"She will be greatly missed. Also I would like to add how much it means to us, what everybody at home and in Manchester have done to support us at this time. Thank you," Fawell's son said in the statement released by police.
Tron died at the concert along with his partner's daughter Courtney Boyle.
Tron's family wrote he was a "fun loving, energetic soul."
"Our most amazing, son , partner, brother, father, uncle, nephew and cousin Philip Tron sadly passed away," the family said in a statement released by the police. "Philip was such a fun loving, energetic soul; he would light up the darkest room and life your spirits with his infectious laugh, witty sense of humor and beautiful smile.
His stepdaughter wrote, "You were always there no matter what, to keep me safe and make me happy."
Boyle's mother wrote a statement for both her daughter and partner, Tron.
"My stunning, amazing beautiful daughter you were my rock you made me so proud with all you had achieved," she said. "Phillip you made my world a happy place and now you are both my angels flying high in the sky."
The teen's sister called her "a shining yellow star in the sky."
The mother of three died after the Ariana Grande concert, according to a statement released by her family to the police.
"Family was her life and we are all obivously devastated by her loss. She has been taken away from us, and all that love her, in the most traumatic way possible," the family said. "We hope to draw from the courage and strength she showed in her life to get through this extremely difficult time."
McIver's family wrote she was a "much loved daughter, sister, Auntie, friend and colleague."
"She was everyone's friend, thoughtful beyond belief with an effervescent and outgoing personality," her family said in a statement released to police.