Rip Joan Rivers -- who made the world laugh for over 50 years with her jokes, put-downs and one-liners has died in NYC ... a week after her heart suddenly stopped beating during vocal cord surgery.
She was 81.
Joan's daughter Melissa Rivers took her mom off life support so she could pass comfortably in a private room.
The death has been reported to the NYC Medical Examiner's Office -- and officials tell TMZ the office will open an investigation to determine cause of death.
