Emery Lynn Mizell was just 17 when she was fatally stabbed by another teen in Soundview in 2024.
Her father called the act the horrifying ending of a month-long cyberbullying campaign.
Now, he's taking Meta and the City of New York to court, accusing them of failing to prevent the violence.
"She was a smart girl, she wanted to be a nurse, she liked to dance," said Tony Mizell, the father of the victim.
He says his whole world has been flipped upside down.
Two years after his 17-year-old daughter was viciously stabbed to death by a 15-year-old girl, he still wonders what more he could've done.
"She cried to me like you know there's a girl who keeps saying things and I just said leave it alone," Mizell said. "I called the school, but the school, you know, that girl wasn't coming to school, so there was no conference that happened."
Her family says it happened after the 17-year-old was on the receiving end of weeks of harassment and bullying online.
She was fatally stabbed outside the assailant's building in the Soundview section of the Bronx.
Emery's father says the suspect waited for his daughter as she was walking to school. She was stabbed in the chest. The assailant was charged with murder.
The victim's father says that before the attack, the suspect threatened to stab his daughter on Instagram.
Her family is now filing a $50 million wrongful death lawsuit against Meta, the city and ACS.
"Meta should be held accountable for what happened here as well as the city agency that's responsible for children," Sanford Rubenstein said.
"The knife that was used was from the family's home, and ACS should have done more to supervise this child," said Mark David Shirian, the Mizell's family attorney.
ACS is reviewing the lawsuit.
Meta declined comment, but states in its policies that content involving threats, bullying and harassment are removed.
"My life is different," Mizell said. "I have to see her sister, who looks just like her. When I go home, it's like my heart just stops all over again. It feels like it happened just yesterday."
He says his youngest daughter now sleeps in the living room to be close to her sister's cremated remains.
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