UPDATE 4:30PM PT: The NY Daily News reports that Joan is in a medically induced coma, and that doctors will bring her out of it this weekend to determine if there has been damage and what kind.

UPDATE: Sources close to Rivers confirm to "Extra" that she has been upgraded to stable condition.

Comedian Joan Rivers, 81, was rushed to Mount Sinai hospital in NYC in critical condition on Thursday morning, reports TMZ. 

Joan Rivers Rushed to Hospital After She Stopped Breathing
Getty Images

The “Fashion Police” star was undergoing surgery on her vocal chords at the Yorkville Endoscopy clinic when she reportedly stopped breathing shortly before 10 AM.

The site says her daughter Melissa Rivers is on her way to NYC to be with her mom.

Just yesterday, Rivers was promoting her new book, Diary of a Mad Diva, at the Time-Life building in Manhattan, reports People.

Story developing.