The victims were struck near West 22nd Street and Neptune Avenue just after 12:30 p.m.
Witnesses say the driver backed into three women on the sidewalk.
An 89-year-old woman was taken to NYU Langone Hospital Brooklyn where she died from her injuries.
A 75-year-old woman and a 43-year-old woman were also taken to NYU Langone where they remain hospitalized.
Police say an 86-year-old driver suffered a medical episode while he was driving. He was taken to Maimonides Medical Center in serious condition but is stable.
Witnesses say good Samaritans came running over to help the victims lying in the street.
One witness says the driver fainted and then woke up dazed and confused.
It was not yet clear if the driver will face any charges.
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