Katherine Helmond Mourned by 'Who's the Boss?' Co-Star Judith Light: 'She Is in My Heart Forever'

Who's The Boss? star Judith Light is mourning the loss of former co-star Katherine Helmond.The [...]

Who's The Boss? star Judith Light is mourning the loss of former co-star Katherine Helmond.

The actress took to Twitter Friday to share sweet words about the Hollywood icon, who passed at the age of 89 at her Los Angeles home on Feb. 23.

"Katherine Helmond was an inspiration to me and so many others," she wrote. "Her grace, talent and humor will be deeply missed. She is in my heart forever."

Helmond passed away from complications of Alzheimer's disease. She is survived by her husband of 57 years, David Christian, and her half-sister Alice.

"She was the love of my life," Christian told The Hollywood Reporter. "We spent 57 beautiful, wonderful, loving years together, which I will treasure forever. I've been with Katherine since I was 19 years old. The night she died, I saw that the moon was exactly half-full, just as I am now … half of what I've been my entire adult life."

Aside from her iconic role as Mona Robinson on the classic ABC show, Helmond also appeared in shows like SOAP and Everybody Loves Raymond. She also co-starred in films such as Time Bandits, Brazil, and Fear and Loathing in Las Vegas.

Who's The Boss? co-star Tony Danza also mourned Helmond's death with a sweet tweet.

"We all lost a national treasure today. No words can measure my love," he tweeted. He included a group of photos with Helmond and the Who's The Boss? cast.

He also shared a statement, which read: "She was such an influence on me. No matter what problem I had, I could go to her. Very few people could match her. She was a consummate professional. She never made a mistake and she always got the laugh. She was the sexy older lady who could keep up with the young people. She just had a way about her."

Co-star Alyssa Milano also shared a heartfelt tribute to Helmond on Twitter.

"Katherine Helmond has passed away," the Charmed actress said. "My beautiful, kind, funny, gracious, compassionate, rock. You were an instrumental part of my life. You taught me to hold my head above the marsh! You taught me to do anything for a laugh! What an example you were! Rest In Peace, Katherine."

Helmond won a Golden Globe for SOAP in 1981 and another for Who's The Boss? in 1989. She earned four Emmy nominations for SOAP, two for Who's The Boss? and one for Everybody Loves Raymond. She was also given a Tony Award nomination in 1973 for her performance in a production of Eugene O'Neill's The Great God Brown.