The details are sparse, but TMZ is reporting that Mary Tyler Moore is in very serious condition at a Connecticut hospital, and has been on a ventilator for more than a week.
Sources close to the family told the online gossip site that people have arrived at the facility to say their goodbyes.
Moore is probably best known for her titular role on the beloved Minnesota-based Mary Tyler Moore Show. Other career highlights include The Dick Van Dyke Show and the Oscar-winning Ordinary People.
Moore has long managed diabetes, and underwent brain surgery in 2011.
We'll keep you posted as more news is released.
[UPDATE]: The Associated Press and other media outlets have reported that the beloved actress has died. Moore's spokesperson gave the following statement to NBC:
"Today, beloved icon, Mary Tyler Moore, passed away at the age of 80 in the company of friends and her loving husband of over 33 years, Dr. S. Robert Levine. A groundbreaking actress, producer, and passionate advocate for the Juvenile Diabetes Research Foundation, Mary will be remembered as a fearless visionary who turned the world on with her smile."