Olivia Newton-John, a pop fixture of the '70s and multiple Grammy winner who expanded her reach with roles in major film musicals, has died at her Southern California home after a decades-long struggle with breast cancer. She was 73.

The Australian singer, actress and activist was a TV star Down Under before trying her luck as a pop act; she sang in a duo with fellow Aussie Pat Carroll and was part of the Don Kirshner-formed group Tomorrow before striking out on her own. She finally hit pay dirt with 1973’s “Let Me Be There,” which earned her a Grammy for Best Country Female. Her big breakthrough, however, came the following year as “I Honestly Love You” went to #1, snagging Record of the Year at the Grammys as well as a trophy for Best Pop Vocal–Female.

Landing the role, at age 29, of high-school senior Sandy in the smash 1978 film musical Grease—the soundtrack to which was a multiplatinum behemoth—made Newton-John a household name; two singles on which she appeared, “Summer Nights” and “Hopelessly Devoted to You,” hit the Top 5 simultaneously. The latter earned an Academy Award nom and she performed it on the Oscars. Meanwhile, thanks to her work in support of animals rights and cancer research and treatment, she was awarded an OBE and became Dame Olivia.

Newton-John co-starred in another screen musical, the fantasy Xanadu, which (despite less-than-stellar box office) spawned a double-platinum soundtrack. She scored further hits in the ensuing years with “A Little More Love,” “Magic” and “Physical,” among others.

Newton-John, who was first diagnosed with breast cancer in 1992 and has been an outspoken advocate and avid philanthropist in leading the fight against it, is survived by her husband, John Easterling, daughter Chloe Lattanzi, sister Sarah Newton-John, brother Toby Newton-John and an array of nephews and nieces.

“Olivia has been a symbol of triumph and hope for over 30 years sharing her journey with breast cancer,” reads an online tribute from Easterling. “Her healing inspiration and pioneering experience with plant medicine continues with the Olivia Newton-John Foundation Fund, dedicated to researching plant medicine and cancer. In lieu of flowers, the family asks that any donations be made in her memory to the Olivia Newton-John Foundation Fund."

Her death has led to significant activity among online music sellers. Fans have pushed seven of Newton-John’s hits into the Top 10 at iTunes songs and seven of her albums into the Top 10.

The Grease soundtrack is the big winner: the 1978 soundtrack is #1 in albums while its hit single, “Hopelessly Devoted to You,” tops the songs chart. The Xanadu soundtrack with ELO is right behind it at #3; the album’s “Magic” is #2 at songs and the title track is #8.

She’s also having quite the run at Amazon where the CD compilation Gold is #1 in the CDs and Vinyl department, the Grease CD is #3 and the LP is #5, the Physical LP is #4 and the CD is #7, and The Definitive Collection CD is #9. In Amazon’s digital department, the 20th Century Masters: The Millennium Collection is #1 and Grease is #4.

Since I was ten years old, I have loved and looked up to Olivia Newton John. And, I always will. (Just like this picture @nfsaonline) She was, and always will be, an inspiration to me in so many, many ways. My deepest condolences to her family and loved ones. x ONJ4EVER pic.twitter.com/3nE8PVDFLy
— Kylie Minogue (@kylieminogue) August 8, 2022

One of the most genuinely beautiful souls has left us. Olivia Newton-John was an amazing artist in every way. She was a dear friend to me and to all. Olivia is the definition of the phrase “Down to earth”. I love you Liv pic.twitter.com/FKyUd7WfRs
— Peter Frampton (@peterframpton) August 8, 2022

My great friend Olivia Newton John has passed away. She was the perfect Lady, gorgeous, with great poise and with a certain Aussie sophistication.
Her spandex trousers in Grease were my inspiration for my ‘Da ya think I’m Sexy‘ era.
RIP Olivia
Sir Rod pic.twitter.com/Suleq8JSkX
— Sir Rod Stewart (@rodstewart) August 8, 2022

Sad to hear of Olivia Newton-John’s passing. She was a beautiful artist and a brave warrior as she battled breast cancer with grace. Rest In Peace, Olivia. pic.twitter.com/Tr2PCD5Tnp
— Sheryl Crow (@SherylCrow) August 9, 2022

Oh man!!! You were my childhood!! Your talent, poise, beauty!! Rest in glorious peace. God bless your family....and thank you for creating eternal memories. â¤ï¸â¤ï¸â¤ï¸â¤ï¸ https://t.co/eaS2wmURIh
— Viola Davis (@violadavis) August 8, 2022

I was also blessed to be in her presence on many other occasions and she was one of the kindest, most generous and lovely people I've ever met. She will be missed. She will be remembered. She will be loved. Olivia, I honestly love you. ðŸ•Šâ¤ï¸ pic.twitter.com/FvwJwcXaO2
— Mariah Carey (@MariahCarey) August 9, 2022

Olivia Newton-John ðŸ•Š pic.twitter.com/5z5uGFpZj1
— Oprah Winfrey (@Oprah) August 8, 2022

In memory of the wonderful life and music of Olivia Newton-John ðŸ’™ pic.twitter.com/JE3kHuDt8K
— The Kelly Clarkson Show (@KellyClarksonTV) August 9, 2022

I didn't know Olivia Newton-John personally but I admired her for the way she faced her health battles. Beautiful & strong, she fought to the end. My heart goes out to her family & all who love her. It's just not fair. Godspeed, Olivia. We'll always be hopelessly devoted to you. pic.twitter.com/X33Yj24SEE
— Nancy Sinatra (@NancySinatra) August 9, 2022