'Grease' star and singer Olivia Newton-John dies aged 73

Australian singer Olivia Newton-John, who gained worldwide fame as high-school sweetheart Sandy in the hit musical movie "Grease," died on Monday, her family said.

She was 73.

Olivia Newton-John and John Travolta pose on the red carpet in Beverly Hills, California. File/ AFP

The entertainer, whose career spanned more than five decades, devoted much of her time and celebrity to charities after being diagnosed with breast cancer in 1992.

Newton-John "passed away peacefully at her ranch in Southern California this morning, surrounded by family and friends," said a statement from her husband John Easterling posted on her official social media accounts.