By Fernando Alfonso III and Melissa Macaya, CNN
The last tweet actress Betty White sent before her death was about her upcoming 100th birthday and the People Magazine cover commemorating it.
The "Golden Girls" actress told the magazine that the key to her upbeat nature was being "born a cockeyed optimist."
White had 1.5 million followers on Twitter.
Read her last tweet:
Betty White leaves behind a career in show business that spans more than 80 years.
She was nominated for 21 Primetime Emmy awards and won five. She was also nominated for one Grammy Award and won one.
Here's a look back at key moments from White's career.
Read more about White here.
From CNN's Marianne Garvey
Betty White, former Golden Girl and national treasure, was set to turn 100 on Jan. 17 and was inviting fans to celebrate with her in a special movie event called "Betty White: 100 Years Young — A Birthday Celebration."
The movie, made by Steve Boettcher and Mike Trinklein, follows White in her day-to-day life, including behind-the-scenes on sets, working with her office staff, entertaining at home, lending her voice as an animal advocate and taking viewers to her actual birthday party.
A star-studded cast of friends including Ryan Reynolds, Tina Fey, Robert Redford, Lin Manuel- Miranda, Clint Eastwood, Morgan Freeman, Jay Leno, Carol Burnett, Craig Ferguson, Jimmy Kimmel, Valerie Bertinelli, James Corden, Wendy Malick, and Jennifer Love Hewitt join her.
From CNN's Megan Thomas
Betty White, the self-described "lucky old broad" whose sweetly sarcastic senior citizen characters were a beloved fixture on TV shows and movies such as "The Golden Girls," "Boston Legal" and "Hot in Cleveland," died Friday, her longtime agent Jeff Witjas said in a statement to People magazine.
"Even though Betty was about to be 100, I thought she would live forever," Witjas said. "I will miss her terribly and so will the animal world that she loved so much. I don't think Betty ever feared passing because she always wanted to be with her most beloved husband Allen Ludden. She believed she would be with him again."
At 99, White was just weeks away from celebrating her 100th birthday.