It happened Tuesday around 8:30 a.m. on a northbound D train near 9th Avenue in Borough Park, Brooklyn.
Police said 40-year-old Anna Lushchinskaya, of Sheepshead Bay, faces felony assault charges after she yelled profanities at a 24-year-old Asian woman and struck her with an umbrella handle and keys.
Videos on social media from the incident showed what appeared to be Lushchinskaya making racist slurs at both the victim and a good Samaritan who intervened, but police have not charged the suspect for bias crimes.
WARNING: The videos below contain strong language. Viewer discretion is advised.
"Everybody was just looking at each other like, 'Are you sure you just heard that? Did you just hear that?'" said Juan Ayala, speaking exclusively with ABC7 sister station WABC-TV.
Ayala is the man who stepped in to try and stop the outburst.
"I'm lucky that she didn't have anything like weapons on her -- like a knife, gun -- because it could have got a lot worse," the victim, who wishes to remain anonymous, said. "I'm lucky that people were on the train who were helping me, especially the first Asian guy who stood in front of me right away because he wasn't recording. He just stood in front of me to help me, because I know other people were recording, but their recording didn't do anything until later on when it escalated."
The dispute began after the suspect bumped into the victim, police said.
Juan Ayala held Luschchinskaya for police, but was worried about the victim.
"It's something that can almost be traumatizing, honestly," Ayala said. "It's not a situation that anybody should be involved in, especially a little girl."
The victim suffered lacerations to her face. The good Samaritan also suffered scratches.
Lushchinskaya was apprehended at 36th Street and placed under arrest.
Then she tried me so I had to detain her until the cops showed up 🤦🏾♂️ pic.twitter.com/C3UybusAxa— PL∆T∆NO M∆N™ (@PlatanoMan) December 12, 2018
"Coming home, I couldn't breathe," the victim said. "Every time I have to get a train, I'm really careful where I'm watching."
A criminal complaint from June shows that Lushchinskaya was charged in connection with another D train scuffle.
According to the complaint, Lushchinskaya allegedly pepper-sprayed a man on the train at the 36th Street station.