A woman died after being shoved in front of an oncoming subway in the heart of Times Square Monday, and a woman arrested in the deadly shove may be linked to another subway death, police sources familiar with the investigation tell NBC 4 New York.

Police and firefighters swarmed the Times Square station at 42nd Street shortly after 1 p.m. after getting a report of a person pushed in front of a train. The 49-year-old victim was pronounced dead at the scene.

The suspect, 30-year-old Melanie Liverpool of Queens, was taken into custody at the scene and later charged with second-degree murder, police said.

It wasn't clear if the suspect and the victim knew each other, nor was it known if they had some type of dispute prior to the alleged shove.

"It's a horrible incident," said NYPD Chief William Aubry. "Your heart goes out to this victim and her family."

Witnesses who saw the push were also being interviewed at the precinct in the station.

Law enforcement officials say Liverpool previously claimed to police she had shoved another person in front of an oncoming train at Union Square station on Oct. 19.

At the time, police did not find her claim credible; two different witnesses told investigators the victim had jumped in front of the train and treated the death as a suicide, officials said.

Now the NYPD is reexamining the subway death, law enforcement officials said.

Liverpool has a history of mental illness, police say.

Subway deaths from pushes are not common, but there have been a few in the past few years. In 2014, Kevin Darden, 34, was charged with killing a 61-year-old immigrant from Hong Kong, Wai Kuen Kwok, by shoving him into the path of a subway train in the Bronx. He pleaded guilty to manslaughter and is awaiting sentencing.

In 2012, Erika Menendez, a mentally ill woman who had a history of attacking strangers, shoved an immigrant from India off a subway platform in Queens. She pleaded guilty to manslaughter and was sentenced to 24 years in prison. The victim, Sunando Sen, was 46.

Also in 2012, a homeless man, Naeem Davis, was arrested and charged with shoving Ki-Suck Han, a Korean immigrant, into the path of a subway train at a station near Times Square.

A fatal subway push in 1999 led to a state law, known as Kendra's Law, that allows supervision of certain patients outside of institutions to make sure they're taking medications and don't present a public safety threat. It came after the death of Kendra Webdale, who was pushed to her death by a former mental patient.