It happened at the 57th and 7th station in Midtown just before 11:30 a.m. Saturday.
Police say the 70-year-old victim was approached from behind by an unidentified man who pushed her onto the tracks.
She was pulled back up to the platform by bystanders.
The victim was taken to the hospital with a laceration to her head.
Police say the person of interest was taken into custody and their investigation is ongoing.
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