Olivia Newton-John has died, according to a statement from her husband posted to her official Facebook and Instagram pages. The venerable Australian singer-songwriter and actor, whose decades-long career resulted in over 100 million albums sold, passed away at her ranch in Southern California on Monday morning (August 8). She died due to undisclosed causes. Newton-John was 73 years old.

Newton-John’s death follows a battle with breast cancer. She was initially diagnosed with the disease in the early 1990s. She fought multiple rounds of the disease, which returned in 2013 and 2017, when Newton-John announced that it had also spread to her back and into her bones. Throughout, she remained active and outspoken about her illness, founding the Olivia Newton-John Cancer & Wellness Centre (ONJCWC) in the process.

Newton-John’s career began at an early age. After being part of various musical groups from the age of 15, she released her debut U.S. album Let Me Be There in 1973, with the title track marking her first American top ten single. Her career skyrocketed in 1978, when she was cast as Sandy, the female lead alongside John Travolta’s Danny in Grease. The role made Newton-John a household name. Her most successful album, Physical, would follow in 1981. The pinnacle of her solo career, Physical was a video album, and won the Grammy Award for Video of the Year.

Newton-John continued to perform and record into the later years of her life—while her last studio album A Celebration in Song was released in 2008, live and holiday albums (including 2012’s This Christmas with John Travolta) were issued as late as 2016. Her last single was 2018’s “Don’t Stop Believin’.”