Olivia Newton-John Sends Condolences to 'Grease' Co-Star John Travolta After Kelly Preston's Death

Singer Olivia Newton-John sent her condolences to her Grease co-star John Travolta after his wife, Kelly Preston, died late Sunday. Preston passed away after a two-year battle with breast cancer at age 57. Newton-John has been a longtime advocate for breast cancer research, following her diagnosis with the disease.

"Kelly was a radiant, warm and gentle spirit -- a loving, devoted wife, mother and sweet friend," Newton-John said in a statement to Entertainment Tonight. "My heart breaks for John, Ella, and Ben. No words can express my sorrow for her family. Kelly's light shines on in her beautiful children." She released the statement just hours after Travolta shared the sad news himself on Instagram.

"She fought a courageous fight with the love and support of so many," Travolta wrote of Preston. He went on to thank her doctors and nurses at M.D. Anderson Cancer Center and other medical centers where she received treatment, as well as her friends and family who stayed by her side. "Kelly's love and life will always be remembered," Travolta wrote. "I will be taking some time to be there for my children who have lost their mother, so forgive me in advance if you don't hear from us for a while. But please know that I will feel your outpouring of love in the weeks and months ahead as we heal."

Preston is survived by Travolta and their two children, daughter Ella Bleu, 20, and son Benjamin, 10. Their son Jett died in January 2009 at age 17, following a seizure during a family vacation in the Bahamas. Travolta and Preston said Jett was diagnosed with autism and suffered seizures throughout his life.

Newton-John was first diagnosed with breast cancer in 1992 and was diagnosed again in 2013. In 2017, she was diagnosed with Stage 4 breast cancer. During an appearance on the Australian talk show The Project, the "Physical" singer said her health was "fantastic" and she is "doing really well." She does not believe her cancer is still in stage 4. "I believe your belief system is part of the healing... at my last MRI, which is an exam where they look inside, things are shrinking, going away, staying the same and I'm living well with it, and I'm feeling great," she said at the time.

Travolta and Newton-John have remained close friends in the four decades since they co-starred in Grease. Last winter, they even made appearances in Florida for "Meet N Grease" events, in which they screened the movie and took questions from fans. "She doesn't look any different than [she did] years ago, and I'm very proud of her," Travolta told ET in August 2019. "I'm very happy about Olivia."