Story highlights

Olivia Campbell, 15, had been talking about the Ariana Grande concert for weeks

More than 150,000 people shared posts seeking information about Olivia

CNN  — 

The mother’s dread and fear gripped parents around the world in less than a day.

For 24 hours, Charlotte Campbell suffered the most harrowing anxiety imaginable. Her daughter, 15-year-old Olivia Campbell, didn’t pick up her phone after the gruesome attack outside an Ariana Grande concert.

Sobbing, Charlotte Campbell took to international airwaves, pleading for anyone who may have seen Olivia to please come forward.

“It’s the most horrible feeling ever – to know that your daughter’s there, you can’t find her, you don’t know whether she’s dead or alive,” she told CNN’s Don Lemon shortly after the Monday night blast.

Within hours, more than 150,000 people shared Campbell’s Facebook posts asking for information.

But her day of agony ended in heartbreak. Campbell learned her daughter was one of the 22 people killed at the concert.

“RIP my darling precious gorgeous girl Olivia Campbell taken far far to soon,” Campbell posted.

She also told her daughter, who loved to sing to herself, “go sing with the angels and keep smiling mummy loves you so much.”

Teen’s final moments of bliss

Olivia spent her final hours living out a fantasy – seeing Grande perform live.

She went to the concert with her friend Adam, her mother said. For weeks, the giddy fans wouldn’t stop talking about the upcoming show.

“It was a treat for Adam’s birthday,” Campbell said shortly after the attack. “They’ve done nothing but talk about it, been excited for it, buying new clothes for it.”

When Olivia finally made it to Manchester Arena on Monday night, she did what many teens probably wouldn’t do – she called her mom to thank her.

Olivia talked about how thrilled she was as she waited for Grande to take the stage.

“She thanked me and said she loved me,” Campbell said. “And that was the last I heard from her.”

The mother said she can’t fathom how anyone could attack innocent children.

The victims were “normal children … going to see one of their favorite artists,” she said. “And it ended in absolute carnage.”

CNN’s Samantha Beech contributed to this report.