It happened at about 11 a.m. at the intersection of East 141st Street and Beekman Avenue in the Mott Haven section.
Police say a 2013 gray Infiniti was going southbound on Beekman when it hit Candida Acosta as she was walking east on 141st Street.
Acosta was pronounced dead on arrival at Lincoln Hospital.
"I'm the one who checked to see if her pulse was there and her pulse wasn't there, I called emergency, everything was leaking, they told me try to help, what's there to help her," said Acosta's friend, Mercedes Rivera.
Friends called her Candy, and said she never saw the Infiniti coming, that the woman had no time to get out of the way as the car came barrelling towards her.
"She was crossing the street and all of a sudden the van came and pow, oh my Lord," said friend Victor Corcino.
The car was coming down Beekman with a woman driving, and her 8 year old daughter was also in the car.
Horrified neighbors say they watched helplessly as the vehicle blew the stop sign at the corner, made the turn on 141st and hit Acosta.
It kept going, striking the wall of an apartment building, and finally stopping when it crashed into the cement staircase.
The driver did stay at the scene.
"If that building wouldn't have stopped that car, all those people would have died plus people that are on that sidewalk," said Rivera.
Acosta lived in a building on Beekman, and friends say her husband, who was too upset to talk, lived around the corner.
Friends say even though the couple was separated, she would bring him food everyday.
In fact, everyone in the neighborhood had only good things to say about her.
"I spoke with her everyday and it was sad to see her like that, she just gave me a lot of strength to keep going," said friend Felecia Wims.