A New York City woman who plunged to her death in the East River on Friday refused a life jacket rescuers tossed to her, police told the New York Post of her apparent suicide.

Witnesses said the unidentified woman, in her 30s, jumped into the freezing river from a ferry dock in Brooklyn at around 7:40 p.m., police told the newspaper. A ferry operator warned her to step back from the edge of the dock but was forced to watch as she continued forward and jumped.

Workers at the scene tossed her a life jacket, but she refused it and was carried by the tide about three blocks south from the North Williamsburg dock.

NYPD harbor officers and firefighters rushed to pull her from the 40-degree water but were stalled by floating chunks of ice.   

"She was in there for a long time," an unnamed firefighter told the newspaper.

Paramedics performed CPR on the woman after she was pulled from the East River and rushed her to Woodhull Hospital. She did not make it.

Investigators initially thought her jump was an accident but later determined it to be suicide. It was not immediately clear what led to the fatal incident.