Photo:Kyle Mazza/Anadolu via Getty; Theodore Parisienne/New York Daily News/Tribune News Service via Getty

Woman Set on Fire Coney Island-Stillwell Avenue Station in Brooklyn, Sebastian Zapeta

Kyle Mazza/Anadolu via Getty; Theodore Parisienne/New York Daily News/Tribune News Service via Getty

Debrina Kawam, a 57-year-old resident of New Jersey, died from “thermal and inhalational injuries,” the New York City Chief Medical Examiner confirmed to PEOPLE on Tuesday.

Thermal burns can occur when heat sources, upon contact with the skin, raises the temperature of the skin and tissues,resulting in tissue cell death or charring.

Inhalational injuries can result frombreathing in toxic substances,such as smoke (from fires), which affects the respiratory system and lungs.

Kawam’s manner of death has been ruled a homicide, per the ME’s office.

Sebastian Zapeta-Calil, 33, wasarrestedfollowing the attack and has since been indicted onmurder and arsoncharges in connection with the killing.

The incident occurred on Dec. 22 while Kawam was asleep on an F train in Brooklyn’s Coney Island; the suspect “calmly" approached her,New York Police Commissioner Jessica Tischsaid at a press conference last week.

NYPD Chief of Transit Joseph M. Gulotta said at the press conference that Kawam was sitting “motionless” when the suspect approached her, and there was no interaction between the two prior to the attack.

The suspect then allegedly used what investigators believe was a lighter to set fire to Kawam’s clothing which was “fully engulfed in flames in a matter of seconds,” Tisch said.

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Kawam was a resident of Toms River, N.J., per the NYPD.

Zapata hasbeen indictedon charges of first-degree murder, second-degree murder and first-degree arson, which could land him in prison for life without parole. He has not yet entered a plea, and is due back in court on Jan. 7.

source: people.com