John Travolta Mourns 'Grease' Costar Olivia Newton-John's Death

Olivia Newton-John has passed away at 73 following a years-long battle with breast cancer, and now, her loved ones are mourning her death.

John Travolta, who stars as Danny Zuko, the love interest to Newton-John's Sandra Dee "Sandy" Olsson, in the cult-classic film Grease, shared his sadness over the news of her death this afternoon.

"My dearest Olivia, you made all of our lives so much better. Your impact was incredible. I love you so much. We will see you down the road and we will all be together again. Yours from the first moment I saw you and forever! Your Danny, your John!" he wrote on Instagram alongside an old photo of the beloved actress.

The two stayed close friends since the release of the movie in 1978, and even reunited for a Grease sing-along in 2019. Newton-John took to Instagram to share a behind-the-scenes photo of the two holding hands in their old Sandy and Danny wardrobes. "First time in costume since we made the movie ! So excited!!" she wrote in the caption at the time.

Newton-John's husband, John Easterling, confirmed her passing today by sharing a message on her Facebook and Instagram pages. It read, "Dame Olivia Newton-John (73) passed away peacefully at her Ranch in Southern California this morning, surrounded by family and friends. We ask that everyone please respect the family's privacy during this very difficult time."

Her rep said the actress "died peacefully at her ranch in Southern California Monday morning, surrounded by family and friends."

Newton-John had been battling cancer since 1992. She was first diagnosed with the disease that year, and then in 2017, more than two decades after she recovered, the cancer returned. Due to her experience with the disease, the star dedicated most of her life outside of Hollywood and the music industry to advocating and raising funds for cancer research, through her Olivia Newton-John Cancer Wellness & Research Centre in Melbourne, Australia, and her Olivia Newton-John Foundation.

"Olivia has been a symbol of triumphs and hope for over 30 years sharing her journey with breast cancer. 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 @onjfoundation," Easterling wrote in his statement today.

This article originally appeared on Harper's BAZAAR US.