General Hospital and Knots Landing alum Donna Mills, who played Madeline West Reeves on the former, and Abby Fairgate Ewing on the latter, is among the many celebrities who are posting heartfelt tributes to the late, great Catherine O'Hara. The Home Alone mom passed away on Friday, January 30, after a brief illness. General Hospital, Mills remembers O'Hara View this post on Instagram Instagram Post"I'm thinking about the passing of Catherine O'Hara," Mills somberly began an Instagram reel on her official account. "It's such a shock, and although I never had the honor of working with her, I met her several times and found her to be the loveliest person."And she certainly is a giant in our industry, an amazing actress who did the entire scope of roles that a woman could do," the Knots actress continues. "I want to send my sincere condolences to her family," Mills compassionately added. "I know she will be missed by you, and she'll be missed by the entire industry."The famous General Hospital star O'Hara imitated View this post on Instagram Instagram PostO'Hara, a native of Toronto, began her TV career in Canada, appearing on the 1975 comedy show, The Wayne & Shuster Show. From 1976 to 1980, she appeared on SCTV (originally titled Second City TV), a sketch comedy show similar to Saturday Night Live. There, she created many original characters and imitated stars, including movie legend Elizabeth Taylor (ex-Helena Cassadine, General Hospital). In the Instagram post above, O'Hara recreated her Taylor impersonation for Johnny Carson on The Tonight Show in 1990. The actress hit the big screen as Delia in Beetlejuice. She appeared regularly on TV, guest-starring on comedy shows including Dream On and The Larry Sanders Show. O'Hara's known for playing Kevin's (Macaulay Culkin) mom in Home Alone and Home Alone 2: Lost in New York. Other films and TV for O'Hara were Best in Show, Surviving Christmas, Curb Your Enthusiasm, Six Feet Under, and Modern Family. In 2015, O'Hara was cast alongside former SCTV alum Eugene Levy in Schitt's Creek, a critically acclaimed comedy about a wealthy family that loses nearly all their assets, except for a small town known as Schitt's Creek. O'Hara played Moira Rose, a former soap opera actress. The role earned O'Hara a Primetime Emmy for Outstanding Lead Actress in a Comedy Series in 2017. The actress also won a Golden Globe for playing Moira in the category of Best Actress – Television Series Musical or Comedy in 2020. Last year, O'Hara starred in two series -- HBO Max's The Last of Us in which she played Gail Lynden, and Apple TV's The Studio as Patty Leigh. O'Hara received Primetime Emmy nominations for both roles. Another General Hospital star, James Patrick Stuart (Valentin), also shared his feelings about O'Hara. You can read that story here.