Flowers adorn the Hollywood Walk of Fame star of a comedic icon as the world says goodbye to Joan Rivers.<br/> <br />The acid-tongued comic, known for her sharp wit and classic put-downs died Thursday (September 4), a week after her heart stopped beating during an outpatient medical procedure.<br/> <br />She was 81 years old.<br/> <br />Her groundbreaking career paved the way for countless female comedians, like Kathy Griffin, who paid tribute to the star on Twitter, writing, "A legend, a friend, a mentor, an icon and wildly funny. One of a kind. RIP."<br/> <br />Sarah Silverman tweeted "My heart is torn in half. She wasn't done."<br/> <br />Rivers' can-do spirit kept her working right up until the end, on television, writing books, and performing at small comedy clubs.<br/> <br />Fans of Rivers gathered outside New York's Mount Sinai hospital, where she passed away.<br/> <br />SOUNDBITE: Unidentified fan, saying (English):<br/> <br />"She did a lot for women in comedy and it's really sad to see, you know, she was really kin
