It happened Tuesday afternoon at an apartment building on Ocean Parkway in Kensington.
Police say the 86-year-old woman slipped out while trying to shut the window.
She landed in a grassy area in front of the building.
The woman was transported to Maimonides Medical Center where she was pronounced dead.
A neighbor who has known the woman for 20 years said she was a good, friendly woman.
Another said the victim would always go up and hug her when she saw her coming and going.