Singer Taylor Swift has said the knife attack at a dance workshop themed around her music which left three children dead and nine more injured has left her "completely in shock".
Children and adults were attacked at the event on Hart Street, Southport, on Monday.
Posting on Instagram, the star said she was "at a complete loss" for how to convey her sympathies.
Her fans have raised more than £100,000 for the families of the victims of a knife attack on Merseyside.
Swift, who played in nearby Liverpool as part of her European tour in June, said the "horror" of the attack, which had left three children dead, five critically injured and three more hurt, was "washing over her".
She said the "loss of life of life and innocence" and the "horrendous trauma inflicted on everyone who was there" had left her at a "complete loss for how to ever convey my sympathies to these families".
A crowdfunding page called Swifties for Southport has raised more than £102,000 for Alder Hey Children's Hospital, where many of the injured have been treated.
The Taylor Swift UK & EU Facebook group organisers said the money would go to the hospital's charity arm.
In a statement, the group said it was working with the hospital to "help raise money for the families affected by the tragedy in Southport".
It said it was also "raising funeral funds for the two young Swifties who have tragically passed".
They added that every donation would go to the hospital's charity and would "help make a difference to those impacted in a time of great sadness".
The attack also left two adults critically injured.
A 17-year-old boy, from Banks in Lancashire, has been arrested on suspicion of murder and attempted murder over the attack.
Police said the motivation for the attack was "unclear" but it was not being treated as terror-related.
