I first read about Nia Wilson on a Tuesday night in an Instagram post. This is why we are saying her name: On Sunday night, July 22, she was riding the BART train with her sisters in San Francisco. They got off to switch trains, and while they were on the platform, a man came up to her and her sister, Lahtifa, and stabbed both of them in the neck. Lahtifa was injured but survived; Nia died from her injuries. She was 19 years old.