Carol Ann Susi, a memorable character actress on The Big Bang Theory, has passed away at the age of 62.

The actress known for giving an unforgettable voice to an unseen character on The Big Bang Theory passed away yesterday after a battle with cancer. Carol Ann Susi, known to fans of The Big Bang Theory as the voice of Howard’s eternally-irate mother, was 62.

Susi’s character has never been seen on screen on The Big Bang Theory, though Mrs. Wolowitz’s formidable bulk has been a long-running joke on the show. But over The Big Bang Theory‘s eight seasons, Susi provided an impressive characterization for “Ma,” as she is affectionately known. Barking out orders, complaints, pleas, and praise for her beloved Howie, Susi’s voice painted a vivid picture of the woman who looms so large in Howard’s life.

In a statement, CBS, Warner Bros., and The Big Bang Theory‘s executive producers expressed their sadness.

“The Big Bang Theory family has lost a beloved member today with the passing of Carol Ann Susi, who hilariously and memorably voiced the role of Mrs. Wolowitz. Unseen by viewers, the Mrs. Wolowitz character became a bit of a mystery throughout the show’s eight seasons.

“What was not a mystery, however, was Carol Ann’s immense talent and comedic timing, which were on display during each unforgettable appearance. In addition to her talent, Carol Ann was a constant source of joy and kindness to all. Our thoughts and deepest condolences are with her family during this time, and we will miss her greatly.”

Cast members have also shared their thoughts on social media.

“So grateful to have known Carol Ann Susi who brought laughter & light with her always,” said Melissa Rauch, who plays Bernadette. “She’ll forever be in my heart.”

Mayim Bialik (Amy) called Susi “Our dear friend and castmate,” adding “rough day…” And Kunal Nayyar (Raj) said, “My heart is broken. I will miss your smile. Your spirit is forever with us.”