A suspect in the fatal stabbing has now been charged the woman's death.
Police say around 9:15 p.m. Monday, 30-year-old LaTanya Watson and a 20-year-old woman got into an argument on the 3 train.
They both got off at the Sutter Avenue station. The stabbing occurred upstairs in the mezzanine.
That's where Watson was found with stab wounds to her neck, face and arm.
"I was so shocked. I said I couldn't believe it ... I was really hurt to know that a young girl just riding the train, and over an argument, she gets killed," Brownsville resident Yvette McFarlane said.
"It just kind of makes me a little nervous. God, that could've been my family," said Brownsville resident Andre Jones.
According to officers, Watson pepper-sprayed 20-year-old Mia Simmons, who retaliated with a small knife.
Witness video showed the devastating aftermath. Crowds gathered as Watson was carried out and rushed to Brookdale Hospital, where she was later pronounced dead.
Simmons was later charged with first-degree manslaughter and criminal possession of a weapon.
"I was just surprised. I was worried about my sisters because that could've been my sister or my mother," Brownsville resident Rasheed Irwin said.
"Two lives have changed. Can you imagine?" said Brownsville resident Charlene Hunter. "We just need to keep our awareness up."
Watson's fiancé, Jerelle Martin, told CBS2's Nina Kapur that Watson was on her way home from work at the Fairway grocery store in Red Hook when the stabbing happened.
"I waited for her a couple of hours. She didn't show. I texted her, 'Are you OK?' No answer," he said. "Thirty minutes after those four hours I waited, detectives knocked on the door."
Martin said his fiancée never encountered any problems or got into fights with anyone. She leaves behind a young son.
"She was the most beautiful woman I ever met in this world. And these females took her life. It still does not feel real," Martin said.
Simmons accidentally stabbed herself in the arm during the struggle, and investigators were able to follow that blood trail to her grandmother's home, police said.
Anyone who has any information is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-8477 or for Spanish, 1-888-577-4782. Tips can also be sent to the NYPDTips Twitter account or submitted online at NYPDCrimeStoppers.com.
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