John Travolta, other stars mourn the death of Olivia Newton-John

The entertainment world is mourning the loss of Australian pop legend and actress Olivia Newton-John, who died Monday morning after a long battle with cancer.

John Travolta, who famously starred opposite Olivia in the 1978 film adaptation of the hit Broadway music Grease, posted a heartfelt message paying tribute to her on his Instagram page.

“My dearest Olivia, you made all of our lives so much better,” Travolta writes. “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!”

Newton-John played Sandy Olsson in Grease, while Travolta portrayed her high school love interest, Danny Zuko. The film’s chart-topping soundtrack yielded three smash hits, including the duets “You’re the One That I Want” and “Summer Nights,” which peaked at #1 and #5, respectively, on the Billboard Hot 100. Olivia also scored a #3 solo hit with the Grease tune “Hopelessly Devoted to You.”

Newton-John and Travolta also co-starred in the 1983 romantic comedy Two of a Kind.

Tributes to Olivia continue to pour in from a variety of celebrities. Here are a few:

Cyndi Lauper: “I’m so sorry to hear the news about #OliviaNewtonJohn. She was such a nice person and a radiant bright light. She will be missed.”

Brian Wilson: “Sad news about Olivia Newton John passing.”

Richard Marx: “My heart is broken. Rest now, sweet friend. You were as kind and loving a person as there’s ever been. I’ll miss you every day.”

Melissa Etheridge: “Journey well, dear friend. She was one of the first to reach out to me after my cancer diagnosis. What a beautiful woman and special talent. Hard to know what to say. She will be missed.”

Dionne Warwick: “Another angelic voice has been added to the Heavenly Choir. Not only was Olivia a dear friend, but one of the nicest people I had the pleasure of recording and performing with. I will most definitely miss her. She now Rests in the Arms of the Heavenly Father.”