Taylor Swift issued a statement on Instagram Tuesday expressing her “horror” and “shock” after three children died following a mass stabbing Monday at a Swift-themed dance and yoga class in Southport, England. Several other children are injured or in critical condition after the attack, as well as two adults.

“The horror of yesterday's attack in Southport is washing over me continuously, and I'm just completely in shock…” Swift wrote on her Instagram Stories Tuesday. “The loss of life and innocence, and the horrendous trauma inflicted on everyone who was there, the families, and first responders. These were just little kids at a dance class. I am at a complete loss for how to ever convey my sympathies to these families.”

According to Merseyside Police, the law enforcement responsible for the seaside town of Southport, a 17-year-old male suspect has been arrested after allegedly walking into a two-hour Taylor Swift Dance and Yoga workshop for elementary-aged kids with a knife and stabbing several attendees. Three girls, ages 6, 7, and 9 years old, have died as a result of their injuries, police confirmed.

Prince William and Kate Middleton also shared a sympathetic message on social media after the incident.

Signed “W&C,” the Waleses wrote, “As parents, we cannot begin to imagine what the families, friends and loved ones of those killed and injured in Southport today are going through.”

“We send our love, thoughts and prayers to all those involved in this horrid and heinous attack,” they continued. “Thank you also to the emergency responders who, despite being met with the most horrific scenes, demonstrated compassion and professionalism when your community needed you most.”

Swift continues on the European leg of her long-running Eras Tour, and will return to London for a second series of shows at Wembley Stadium in mid-August.

A representative for Taylor Swift did not immediately respond to Vanity Fair’s request for comment.