After turning in back-to-back Fashion Police episodes on the Emmys and VMAs, Rivers flew to New York City for an appearance at the Time Life building on Wednesday night promoting her book, "Diary 0f a Mad Diva."
Fans posted gushing tributes on social media.
Twitter user Hannah Murray posted a shot of the crowd waiting for Rivers around 6 p.m. EST.
“She is fregging amazing!” eyewitness David Lee Tracy wrote. “Absolutely no filter! #legend”
Just hours later, around 9:39 ET, a 911 call was placed to local New York authorities when Rivers was found to have stopped breathing during a vocal chord surgery. According to reports, the caller said, “We have somebody in either cardiac or respiratory arrest.”