NEW YORK (AP) - Joan Rivers was hospitalized Thursday after she was rushed from a doctor's office when she went into cardiac arrest, police and hospital officials said.
In a statement, Melissa Rivers said her mother was "resting comfortably" with family. She did not elaborate on the 81-year-old comedian's condition.
"We ask that you continue to keep her in your thoughts and prayers," Melissa Rivers said. She offered thanks for the "overwhelming love and support for my mother."
Earlier Thursday, The Mount Sinai Hospital spokesman Sid Dinsay confirmed that Rivers was brought there in the morning.
New York City police officials, who spoke on the condition of anonymity because they weren't authorized to publicly name Rivers, said she was taken to the hospital just after 9:30 a.m. Thursday. It was unclear why she was visiting the doctor's office.
Rivers' representatives didn't immediately respond to requests for comment.
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.
Rivers spoke at an employee event at Time Inc. in New York on Wednesday night and appeared healthy, practically jogging 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."
Rivers took questions and said she wakes up every morning and "is thankful that everything works," Blum said.
An early and outspoken proponent of cosmetic surgery, Rivers' drastically altered her appearance over the years - and found plenty of material for jokes. ("I've had so much plastic surgery, when I die they will donate my body to Tupperware.")
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 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.
A native of New York, Rivers originally entered show business with the dream of a theatrical career, but comedy became a way to pay the bills while she auditioned for acting roles.
"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."
After proving herself in comedy clubs as a rarity - a woman comedian - Rivers was a smash on her first booking on "The Tonight Show Starring Johnny Carson" in 1965. "God, you're funny," Carson told her.
AP writers Frazier Moore, Jeff McMillan and Tom Hays contributed to this report.