Joan Rivers, who became a comedic star with an act that was a mélange of insult, insecurity, over-the-top cattiness and a nothing-is-sacred philosophy, died on Thursday at the age of 81, her daughter Melissa Rivers said.Rivers, an outspoken advocate of the plastic surgery that gave her a preternaturally preserved appearance, died after suffering cardiac arrest during an outpatient procedure on her vocal cords on Aug. 28 at a clinic in New York that had left her on life support for several days.'My mother's greatest joy in life was to make people laugh. Although that is difficult to do right now, I know her final wish would be that we return to laughing soon,' Melissa Rivers said in a statement announcing her passing.Rivers found fame as a stand-up comedian and TV host before becoming a regular on reality television in her later years as a celebrity-bashing fashion pundit.Onstage, Rivers came across as acidic and manic - sort of Don Rickles in diamonds and a Chanel dress. 'Can we talk?' she would ask her audience in a husky New York accent before delivering a brutal put-down line, such as, 'Elizabeth Taylor's so fat she puts mayonnaise on her aspirin.'When it came to getting a laugh or just being provocative, no topic was taboo for Rivers.'If you laugh at it, you can deal with it - and if you don't, you can't deal with it,' she told a TV interviewer in 2010. 'And don't start telling me that I shouldn't be saying it. ... I would have been laughing at Auschwitz.'Rivers, who was Jewish, said she was only saying what everyone else was thinking and if someone found it mean or inappropriate - too bad.She didn't always like criticism, however, and stormed out of a CNN interview in July when asked how she could be an animal rights activist and still pose in fur on the cover of her book 'Diary of a Mad Diva.'Rivers also drew fire when she said that relatives of the victims of the Sept. 11, 2001, attacks should have been thrilled to get a financial settlement for their loss. She once singled out model Heidi Klum by saying, 'The last time a German looked this hot was when they were pushing Jews into the ovens.' Despite complaints, Rivers steadfastly refused to apologize for either comment.Joan Alexandra Molinsky was born on June 8, 1933, in Brooklyn and grew up there and a nearby town, the daughter of a doctor and a housewife. She graduated Phi Beta Kappa from Barnard College and had a six-month marriage that was annulled before she began pursuing an entertainment career with the last name Rivers, which she borrowed from her agent.Rivers first wanted to be an actress but veered into comedy and wrote sketches for Topo Gigio, a talking mouse character on 'The Ed Sullivan Show' in the 1960s after a friend turned down the $500 job. 'For $500, I'll write for Hitler,' she said in an interview with National Public Radio.She also worked on the seminal reality TV show 'Candid Camera' as a writer and in sketches with unknowing members of the public. She wrote jokes for comedians Phyllis Diller and Bob Newhart before concentrating on her own stand-up act.Rivers' peers in the comedy club scene of New York's Greenwich Village at the time included Bill Cosby, Richard Pryor, Woody Allen and George Carlin, but she said she never felt like she was part of their clique.Her career got a boost in 1965 when Johnny Carson - the undisputed king of late-night TV in the United States - had Rivers on his 'Tonight' show and declared she was a star in the making.By the 1980s, she had well-paying stand-up work, regular TV appearances, an Emmy-nominated album and a best-selling book, 'The Life and Hard Times of Heidi Abramowitz,' based on one of her characters.FALLING OUT WITH CARSONRivers reached a pinnacle in 1983 when Carson crowned her as his regular guest host on the popular NBC television show. But their relationship imploded three years later when she left to start her own late-night talk show on the fledgling Fox network. The two never spoke again and the move to Fox turned out to be the start of a downward spiral for Rivers, both personally and professionally.The Fox show lasted only seven months. It was canceled amid low ratings and much enmity between Rivers' husband-manager, Edgar Rosenberg, and network executives. A few months later, Rosenberg committed suicide.Rivers fell into depression, fought bulimia and endured suicidal thoughts. Her relationship with daughter Melissa fell apart at the time because Melissa blamed her for Rosenberg's death.Rivers had to pull out of a financial trough because Rosenberg's bad investments left her several million dollars in debt. She accepted an offer from a television shopping network to hawk her own line of jewelry and it became a success.From 1989 to 1993 she hosted 'The Joan Rivers Show,' which in 1990 won a Daytime Emmy for outstanding talk show.As she aged, Rivers was a carefully constructed testament to her belief that looks matter a great deal, especially to a woman in show business. She was slim and always well dressed, her hair was immaculately styled and her skin taut and seemingly wrinkle- free.Rivers described herself to People magazine as the 'plastic surgery poster girl' and said strangers would stop her on the street to ask for advice on cosmetic surgery.'Looking good equals feeling good,' Rivers said in her 2008 book 'Men Are Stupid ... And They Like Big Boobs: A Woman's Guide to Beauty Through Plastic Surgery.' 'I'd rather look younger and feel happy than look older and be depressed.'Rivers said she had undergone full face lifts, nose jobs, chin tucks, liposuction, breast reduction, an eye job and botox injections. One of her comedy albums mentioned her plastic surgeon in the credits.In recent years, Rivers found a career niche commenting on celebrity fashion. She was seen along the red carpet at televised award ceremonies asking stars 'who are you wearing?' She also hosted the cable TV show 'Fashion Police' where she mercilessly skewered celebrities' wardrobe choices.Rivers was tough on herself, too. 'I knew I was an unwanted baby when I saw that my bath toys were a toaster and a radio,' she said.Rivers and Melissa also starred in 'Joan & Melissa: Joan Knows Best?' with Rivers living with her daughter.She was the winner on Donald Trump's 'The Celebrity Apprentice' show in 2009. In addition to several best-selling books and writing and directing the movie 'Rabbit Test,' Rivers wrote and starred in the 1994 Broadway play 'Sally Marr ... and Her Escorts,' which was based on the life of comedian Lenny Bruce's mother and earned Rivers a best actress Tony Award nomination.