Joan Rivers Legendary Comedienne Dies at 81

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 says the office will open an investigation to determine cause of death. 

Melissa just issued a statement saying, "It is with great sadness that I announce the death of my mother, Joan Rivers."

"She passed peacefully at 1:17 PM surrounded by family and close friends. My son and I would like to thank the doctors, nurses and staff of Mount Sinai hospital for the amazing care they provided for my mother."

"Cooper and I have found ourselves humbled by the outpouring of love, support and prayers we have received from around the world.They have been heard and appreciated."