A 64-year-old woman was fatally stabbed inside a Manhattan liquor store Wednesday night by a man who later threatened to jump from a nearby rooftop, law enforcement sources said.

The woman’s attacker stabbed her multiple times in the chest inside the store on 3rd Avenue near East 25th Street in Kips Bay at about 10:20 p.m., police said.

The victim and suspect were known to each other, sources said, but it was not clear what the nature of the relationship was.

Police said they recovered a knife at the grisly scene.

The suicidal suspect fled after the attack onto a nearby 3rd Avenue rooftop, sources said.

Police set up an inflatable rescue cushion in the middle of the street as the suspect threatened to jump, sources said.

The man was later taken into custody.