Late Sunday evening, a man fatally stabbed an 18-year-old and wounded her sister on the Bay Area Rapid Transit in Oakland, according to the San Francisco Gate.

Oakland native and singer Kehlani reacted to tragedy in a series of tweets calling on BART and officials to find the assailant. She refers to the suspect as a “murderous white supremecist,” implying that the attack was racially motivated. Both of the sisters are black.

Kehlani bolstered her claim in an Instagram post, calling the stabbing a hate crime. “Making Bay Area citizens aware that a young 18 year old girl was brutally murdered and her sister left in critical condition in a vicious attack by a RACIST/TERRORIST/WHITE SUPREMACIST,” the singer wrote. “This was a HATE CRIME. no “random” bart stabbing.”

The suspect stabbed 18-year-old Nia Wilson in her neck at around 9:45 p.m. local time at MacArthur Station. Wilson attended Oakland High School and was identified by her sister Malika Harris. The other victim was Wilson’s sister Tashiya. 

The man, according to police and BART spokesman Jim Allison, is still at large. “They are searching for a suspect who's described as a white male in his 20s or 30s, heavy build, and short hair. The suspect fled from the train and down into the concourse level of the station and left the station," Allison said.

A witness reported the man coming “out of nowhere," BART officials are reviewing surveillance footage of the incident.

Relatives of the girls quickly gathered at the station following the attack. After the stabbing, Tashiya was taken to a nearby hospital and is reportedly now in stable condition. “She needs her justice...she was just an innocent kid, and she didn’t deserve this,” the victims’ cousin Ebony Monroe told SF Gate, referring to Nia Wilson. “And he did this for no reason.”