Joan Rivers is 'resting comfortably' in a medically induced coma just hours after she performed a typically acerbic show in Manhattan and joked about her own death.

The 81-year-old comic was rushed from an Upper East Side clinic to Mount Sinai Hospital in critical condition on Thursday morning after she stopped breathing during a routine medical procedure.

A picture of health only the day before, Rivers accepted a bouquet of flowers from a fan as she finished her stand-up performance at around 9.30pm on Wednesday.

The entertainment legend even posed for pictures with a fan on the way out of the Laurie Beechman Theatre, only to suffer respiratory failure less than twelve hours later during surgery on her throat.

Her daughter, Melissa Rivers, dashed from LA to New York and arrived at the hospital at around 8pm and was ushered to the 11th floor luxury room in which her mother is now said by doctors to be in a stable condition.

She released a statement thanking everyone for their messages of support and gave a brief update on her mother's condition.

'I want to thank everyone for the overwhelming love and support for my mother,' Melissa Rivers said in a statement.

'She is resting comfortably and is with our family. We ask that you continue to keep her in your thoughts and prayers.'

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Thank you: Joan Rivers accepts a bouquet of flowers from a fan after wrapping up her one hour performance at the Laurie Beechman Theatre on Wednesday night at around 9.30pm

Busy as always: Joan Rivers is pictured here at a press event in New York City on Wednesday evening for her book, 'Diary of a Mad Diva'. She is currently in a medically-induced coma at Mount Sinai Hospital after she stopped breathing during vocal cord surgery

Health drama: Comic legend Joan Rivers, pictured in Beverly Hills on Tuesday, has been rushed to hospital

Melissa Rivers is pictured arriving at Los Angeles airport Thursday to fly to New York after hearing her mother had been rushed to hospital

Family: Melissa, 46, and her son Cooper, 13, rushed to be with the star who is now in stable condition

While doctors are said to be keen to keep her in a coma until the weekend, there is concern about the length of time her brain was starved of oxygen.



But less than 12 hours before she stopped breathing, Rivers was her usual irrepressible self, making jokes about her own longevity and mortality to an audience of around 100.



'She did a joke onstage, she goes, ‘I’m 81 — I could go at any moment,’ said Shade Rupe, 45.



‘I could fall over right here and you all could say, ‘I was there!’



Rupe, who spoke to the New York Daily News, said that Rivers' comedy was as quick-witted as it has always been.



'She was so on,' he said. 'If you had me guess her age, I’d say she was in her 50s. She didn’t miss a step, she didn’t go ditzy, she didn’t forget anything and her timing was amazing.'



Rupe grabbed a picture with the star outside the theater and said that Rivers 'looked fantastic.'



And, as testament to the television hosts vigor, Rivers was even promoting her book, 'Diary of a Mad Diva' before she took to the stage on Wednesday.



Rivers, who has been a fixture on American television since the mid-1960s, was her forthright self according to those who were at the press meet.

When she walked in to take her seat, said Shira Blum, an online project manager. 'She seemed totally healthy,' Blum said. 'She was very energetic, hilarious, funny. And it was such a shock, a surprise to hear the news this morning.'

Star: Joan Rivers (pictured here in 2012 at the New York Fashion Week) has been a fixture of American life for more than 50 years and she is celebrated for her acerbic wit

Rivers took questions and said she wakes up every morning and 'is thankful that everything works,' Blum said.



The entertainer has logged a half-century in show business and gave rise to red carpet commentary - and the snarky criticism that often accompanies it. Her signature red carpet query: "Who are you wearing?"



She continues to maintain a busy schedule, and was to perform a show Friday at the Count Basie Theatre in Red Bank, New Jersey.



That show was postponed because of her hospitalization.



Earlier on Thursday, Rivers' daughter, Melissa, 46, and grandson Cooper, 13, were pictured at Los Angeles airport as they traveled to be by the star's side.

'She’s not conscious, but she’s stable,' said the comedian's aide Graham Reed, to the New York Daily News, which reported the star was in a coma.

'This morning, Joan Rivers was taken to The Mount Sinai Hospital in New York, where she is being attended to,' Sid Dinsay, a spokesman for the hospital, said in a statement this afternoon.

'Her family wants to thank everybody for their outpouring of love and support.'

He said the hospital would provide an update on Rivers' condition as it becomes available.

A source told E! News earlier: 'They were putting a scope down her throat to check her vocal cords. She stopped breathing.'



The source added that the operation was not a major one though Rivers was sedated throughout. It's unclear what medication was used.



TV host Billy Bush said on Facebook that he had exchanged texts with Joan's daughter Melissa who asked him to 'please pray'. Melissa and her son Cooper rushed to be by the star's side.



Hospital: NYPD officers wait outside of the main entrance to Mount Sinai hospital on Thursday

Media: TV station vans are seen outside the hospital in Manhattan where Joan Rivers is now in stable condition

TV host Billy Bush posted about the beloved star on Facebook

The 81-year-old's daughter Melissa, seen here with her mom last year, is in New York and at her mother's bedside at Mount Sinai Hospital

He wrote: 'Praying for Joan Rivers who is in critical condition at Mt Sinai hospital in NY. Texted with Melissa Rivers who said 'please pray.' Already doing that. Joan is beloved around here. A regular guest on Access Hollywood Live she never fails to deliver.



'She taped her post Emmy special Tuesday in LA and was strong. This is out of nowhere. Come on Joan you have to make it. Just think of all the material. Sending love and prayers.'

He later tweeted: 'Per Melissa, The mighty @joan_rivers Is in stable condition. That Means her first joke is coming... :)'



According to the New York Daily News, Rivers' assistant, Graham Reed, was overheard saying 'She's not conscious, but she's stable,' obviously distraught.

Stars took to Twitter to express their shock and to wish Rivers and her family well at this difficult time.

'Get well my friend,' tweeted Kathy Griffin and Ellen DeGeneres wrote, 'I’m thinking about you and sending lots of love your way.'

A host of other stars took to social media and said they were hoping the trail-blazing star recovered.



TMZ reported that an emergency call was placed to 911 at 9:39 a.m. New York time.

The caller told emergency services: 'We have somebody in either cardiac or respiratory arrest.'

The drama unfolded at Yorkville Endoscopy on East 93rd street near Third Avenue, police confirmed.

A woman who answered the phone at the clinic this afternoon told MailOnline: 'I don't know what you're talking about, have a great day!'

According to another E! source, Rivers 'had a lot of energy' and was 'cracking jokes' at a Wednesday event in New York to promote her new book.

Surgery: Rivers stopped breathing while undergoing surgery at Yorkville Endoscopy, pictured, in Manhattan

Shira Blum, an online project manager, said she appeared healthy, practically jogging when she walked in to take her seat.

'She seemed totally healthy,' Blum said. 'She was very energetic, hilarious, funny. And it was such a shock, a surprise to hear the news this morning.'

Rivers took questions and said she wakes up every morning and 'is thankful that everything works,' Blum said.

Similarly on Tuesday, she gave no hint about needed surgery as she taped a special 90 minute edition of her show Fashion Police which aired on E! that same night.

Covering both the Emmy Awards and the MTV VMA's the veteran comedienne's voice did sound raspy but she has become known for her gravelly voice and biting tongue.



Well wishers: Celebrity pals of Joan Rivers posted their thoughts onto Twitter after the news she had fallen ill suddenly

Sweet: Charlie Sheen was among many who tweeted their best wishes to entertainment legend Joan Rivers as she battles for her life in Mount Sinai Hospital in New York

The 81-year-old also recently took part in the ASL ice Bucket Challenge not once but three times after celebrities Anne Hathaway, Sarah Jessica Parker and Tara Reid nominated her.



She was to perform a show Friday at the Count Basie Theatre in Red Bank, New Jersey. That show was postponed because of her hospitalization.

The host of 'Fashion Police' on E! network, Rivers also presides over an online talk show, 'In Bed With Joan' and co-stars with her daughter, Melissa, on the WEtv reality show, 'Joan & Melissa: Joan Knows Best?'



Her latest book, 'Diary of a Mad Diva,' was released this summer.



In 2009, Rivers emerged as the winner of NBC's 'The Celebrity Apprentice.'



A documentary, 'Joan Rivers: A Piece of Work,' premiered in theaters in 2010.

The star's no-holds-barred comedy has made her one of Hollywood's mainstays having a career spanning over 60 years.

School: This is the yearbook photograph of Joan Rivers from 1948 while she attended the Adelphi Academy in Brooklyn Obvious talent: Then known as Joan Sandra Molinsky, Joan Rivers was already known for her wit and intelligence while at school as this yearbook posting proves

Comic legend: Rivers is seen here around 1965. She has been a staple of American culture for half a century

Comic legend: Rivers is seen left and right on the Ed Sullivan show in 1966

Stars: Rivers interviewed Oprah Winfrey while guest hosting the Tonight Show Starring Johnny Carson on January 27, 1986

Glamor: Joan Rivers is seen left and right in full 1980s glamor, big hair and all



She g ave rise to red carpet commentary - and the snarky criticism that often accompanies it. Her signature red carpet query: 'Who are you wearing?'

The often outspoken funny lady - born Joan Alexandra Molinsky - started her career in her native New York performing in comedy clubs across the city and even starred in a play as a lesbian woman with a crush Barbara Streisand in the 1950s.

'Somebody said, "You can make six dollars standing up in a club,"' she told The Associated Press in 2013, 'and I said, "Here I go!" It was better than typing all day.'

Joan started to make a name for herself in the male-dominated comedy world as a guest on The Tonight Show from 1965.



Rivers was a smash on her first booking on 'The Tonight Show Starring Johnny Carson' in 1965. 'God, you're funny,' Carson told her.

She also started landing guest spots on The Ed Sullivan Show. Taken under the wing of Johnny Carson as a writer, Joan further developed her biting wit.

Going on to host Saturday Night Live during the Eighties, the iconic star was awarded her show by for The Late Show Starring Joan Rivers - it was this show that led to a bitter fallout with her mentor Carson and he never spoke to her again before his death.

Only this year was Joan's ban from ever appearing on the Tonight Show lifted by Jimmy Fallon.



The comedian would eventually be fired from her Fox show after she challenged executives' decision to removed her husband Edgar Rosenberg as a producer.