Katherine Helmond, 'Who's the Boss?' and 'Soap' Star, Dead at 89

Katherine Helmond
Photo Archives/ABC via Getty Images

The actress died at her Los Angeles home from complications from Alzheimer's on Saturday.

Rest in peace, Katherine Helmond. 

The Who's the Boss? star died at her Los Angeles home on Saturday, from complications from Alzheimer's, her agency, APA, confirms to ET. She was 89. 

In a statement to ET, Helmond's husband, David Christian, mourned the loss of his wife. "She was the love of my life," he 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."

Helmond, best known for playing Mona Robinson on Who's the Boss?, was nominated for seven Emmys throughout her career. In addition, she starred as Jessica Tate on ABC's daytime-serial spoof Soap, Doris Sherman on the network's Coach, and Lois Whelan, the mother of Patricia Heaton's character on Everybody Loves Raymond. 

The actress also had a successful film career, appearing in three Terry Gilliam movies: 1981's Time Bandits, 1985's Brazil and 1998's Fear and Loathing in Las Vegas. 

Alyssa Milano, who played the daughter of Tony Danza's character on Who's the Boss?, took to Twitter after hearing of Helmond's death to pay tribute to the actress. 

"Katherine Helmond has passed away," she wrote alongside a photo collage. "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."

Danza, who played housekeeper Tony Micelli on the '80s sitcom, honored his former co-star with a heartfelt tweet. "We all lost a national treasure today. No words can measure my love," he wrote.

Judith Light portrayed Helmond's daughter, Angela Bower, on Who's the Boss? and called her an "inspiration."

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

Danny Pintauro, who played Helmond's grandson on the series, also tweeted. "We lost one of the most genuine and kind people I have ever known," he wrote. "There's not a single person who can say otherwise - she was always smiling, full of heart, and had the best advice. I couldn't have asked for a better grandmother and I will miss her so dearly."

Helmond is survived by her husband, Christian, her half-sister, Alice Parry, and many much loved nephews and nieces. Helmond and Christian met at The Hampton Playhouse Summer Stock Theater, where he was the set designer, and she was the star. They married in 1962. A memorial for family and friends is being planned for the near future.