Former "Today" show host Katie Couric has lost her mother and best friend on Thursday, Sept. 4. The television personality confirmed the sad news herself on Twitter, Us Weekly has learned.

The 57-year-old Yahoo News Global anchor said her mother, Elinor Hene Couric, passed away at the age of 91.

"My heart is broken. I lost my mom and best friend. We love you and miss you, Mom/Granny," Couric wrote as caption to a black and white photo of her mother she posted on Twitter.

Couric then continued to lament her loss on Facebook, saying, "She loved fiercely and was fiercely loved. We miss you, Mom/Granny. Elinor H. Couric 1923-2014."

Fans were then quick to echo their condolences to Couric, noted AceShowbiz.

One fan even wrote, "Sorry for your loss Katie...may she rest in peace. Our thoughts and prayers are with you and your family."

In a 2012 Woman's Day interview, the famous author and television journalist gushed about her time with her elderly mother since her father, John Couric, passed away at 90 due to multiple complications brought about by Parkinson's disease in June 2011.

"My mother's day-to-day care took on a new urgency after my father passed away last year," she said at the time.

"Now Mom is living alone, in the same house in Virginia where we grew up...it's full of 55 years' worth of memories, and the thought of leaving it and the life she shared with my dad is understandably overwhelming," she added.

The veteran journalist, who tied the knot with financier John Molner in June, also shared that her mom at that time was not sure if she wanted to stay at a nursing home.

"There are no easy answers," she explained. "Mom sacrificed for us her whole life, and we want to help her age with dignity, as gracefully as possible."

Meanwhile, the Katie Couric-helmed show "Stand Up to Cancer" will be aired live on ABC, CBS, Fox, NBC and 26 cable networks on Friday at 8 p.m., according to Washington Post.

The show, which is composed of musical performances and celebrity appearances, aims to raise money for cancer research.

Some of the celebrities who will take part in the show include: Ariana Grande, Jennifer Hudson, Dave Matthews, Lupe Fiasco, The Who and Common, among others. Jon Hamm, Reese Witherspoon, Jennifer Aniston, and money others will also be in attendance.