Fans of the 1980s sitcom “Who’s The Boss” are in mourning after the death of Katherine Helmond, who passed away on February 23 due to complications from Alzheimer’s disease. She was 89 years-old.

Though she had roles in many television shows and movies, she was arguably best known for playing Mona Robinson on “Who’s The Boss” from 1984-1992. Throughout her career, she won two Golden Globes and was nominated for seven Emmy awards for her work on “Who’s The Boss” and “Soap.”

Stars of “Who’s The Boss” have been paying tribute to Helmond on social media in the weeks since her death.

“Katherine Helmond has passed away,” tweeted Alyssa Milano. “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.”

Tony Danza also commented on her passing.

“She was such an influence on me,” he said. “From being a single guy with a hit show in Hollywood, through my marriage and having kids — she was with me. No matter what problem I had, I could go to her. Very few people could match her.”

“Katherine Helmond was a remarkable human being and an extraordinary artist; generous, gracious, charming and profoundly funny,” said costar Judith Light. “She taught me so much about life and inspired me indelibly by watching her work. Katherine was a gift to our business and to the world, and will be deeply missed.”

Katherine is survived by her husband of 57 years, David Christian.

“She was the love of my life,” Christian said. “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.”

Please keep Helmond’s family and friends in your thoughts and prayers as they continue to deal with this loss.