TORONTO — A 15-year-old girl has been charged with assault after a 16-year-old was beaten during the opening night of Kempenfest in Barrie.Barrie Police say the attack occurred around 10 p.m. on July 31 near Lakeshore Drive and Victoria Street as thousands attended the waterfront festival. The victim suffered a concussion, a chipped tooth and multiple bruises. She was treated in hospital and later released.According to the victim’s mother, the fight began after someone threw a glass jar. A video that circulated widely on social media shows the 16-year-old thrown to the ground, straddled and punched repeatedly in the face and head. The mother said her daughter was left “completely passed out like a rag doll on the cement” while attackers continued kicking her and bystanders stood by watching, laughing, cheering and recording. “Not one person stepped in.”.On August 5, officers charged a 15-year-old girl with assault. She was released on an undertaking with conditions and is scheduled to appear in court at a later date. Her identity is protected under the Youth Criminal Justice Act.Footage also shows a second girl punching the victim, standing over her and kicking her again before backing away.Police have described the attack as violent and expressed concern about those who filmed rather than intervened.Investigators are still seeking the second teenage girl believed to have taken part in the assault. Anyone with information is asked to contact Barrie Police at 705-725-7025.