After news of the attack emerged, Mrs Charlotte Campbell phoned everybody, including hospitals, to try to locate her 15-year-old daughter Olivia.
She last spoke to her daughter on Monday night while she was at the concert. "She had just seen the support act and said she was having an amazing time, and thanked me for letting her go," said Mrs Campbell.
Yesterday, she confirmed on social media that her daughter had been killed. #OliviaCampbell was the top trend on Twitter as the nation grieved for the "music-mad" cheerful girl, the Daily Mail reported.
Next to a photograph of Olivia, Mrs Campbell wrote: "RIP, my darling precious, gorgeous girl Olivia Campbell. Taken far, far too soon. Go sing with the angels and keep smiling. Mummy loves you so much."