A 15-year-old Westchester County girl was arrested Friday after she allegedly fatally stabbed a teenage girl and slashed another during a parade celebrating the local high school basketball team’s state championship, authorities said.

The suspect is accused of fatally stabbing a 16-year-old on Gramatan Avenue in Mount Vernon at around 3:55 p.m., Westchester County District Attorney Mimi Rocah said in a statement on Saturday. The suspect also stabbed a 15-year-old, who was slashed and had other injuries, Rocah said.

Shocking video of the Friday afternoon incident showed a girl brandishing a knife and swinging it openly in a mob of multiple young women fighting near the end of the parade.

Two teenage girls were stabbed in the melee. One suffered non-life threatening injuries and the other victim, a 16-year-old, was “gravely injured” and died as she was being rushed to Jacobi Medical Center, according to a statement from the city.

Police said Saturday they were not releasing the names of the person arrested or the two teenagers who were stabbed. Sources identified the victim as Kayla Breonna Green and her devastated mom posted heartbreaking photos of her child at a recent Sweet 16 party and in the hospital bed.

“I am not strong please pray for me while I try to pray for myself at this point I feel like I want to die and bury with my child,” her mother posted. “she was only 16 and they took my baby away from me I want to die right now,” she wrote. “I don’t even know how to say RIP to my daughter this feels so unreal.”

The event began as a city-wide celebration for Mount Vernon High School’s basketball team.

“I am devastated and completely outraged,” Mayor Shawyn Patterson Howard said in a statement.

The parade kicked off around 11 a.m. with members of the Mount Vernon Knights’ undefeated team snaking through the city in a police-escorted motorcade, passing by 15 other schools city schools before ending at Mount Vernon City Hall for a ceremony where the team was honored for its 12th state title.