Alyssa MilanoandTony Danzaare mourning the loss of theirWho’s the Boss?costar Katherine Helmond, whodiedlast month.

Helmond, who famously portrayed mother Mona Robinson in ABC’sWho’s The Boss?for eight years and Jessica Tate onSoap, died on Feb. 23 of complications from Alzheimer’s disease at her home in Los Angeles, her talent agency, APA, announced. She was 89.

“Katherine Helmond has passed away. My beautiful, kind, funny, gracious, compassionate, rock. You were an instrumental part of my life,” Milano captioned a series of photos of Helmond shared on Twitter Friday.

Who’s The Boss?.ABC Television/Fotos International/Getty

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“You taught me to hold my head above the marsh!” continued Milano. “You taught me to do anything for a laugh! What an example you were! Rest In Peace, Katherine.”

In two follow-up tweets, theCharmedstar shared a clip of the late actress on the show and a GIF of her credit on the series, which she captured with a broken heart emoji.

Danza — who played former baseball player, housekeeper, and single father Tony Micelli in the series — also paid his respects to Helmond.

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Tony Danza & K. Helmond In ‘Who’s The Boss’

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“I was in love with her. She was such an influence on me. From being a single guy with a hit show in Hollywood, though my marriage and having kids — she was with me,” Danza, 67, toldDeadline.“No matter what problem I had, I could go to her. Very few people could match her.”

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KATHERINE HELMOND

Before herWho’s The Boss?run, Helmond earned praise for her portrayal of Tate family matriarch in ABC’s soap opera sitcomSoap(1977-1981).

“We luckily got Jessica fromSoap,” Danza told the publication. “Oh my God, we hit the lottery. She was a consummate professional — never made a mistake and 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.”

source: people.com