(WJW) — Following the death of his good friend Olivia Newton-John Monday, actor John Travolta took to Instagram to honor her life.

“My dearest Olivia, you made all of our lives so much better,” Travolta said in a post. “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 moment I saw you and forever! Your Danny, your John!”

The pair got to know one another in 1978’s “Grease,” playing the two main characters Danny Zuko and Sandy Olsson. 

The two lifelong friends were seen together through the decades, including in 2018 in celebration of the 40th anniversary of the fan favorite film.

“You can see from the energy on that film, we were so anxious to get it right that I think everything — it was like going to school,” Travolta told Variety then. “Every day there was a regimen: song, dance, recording, rehearsing scenes, rewriting scenes. It was a big myriad of events.”

The Grammy award-winning star was reportedly surrounded by those she loved most when she died at her California home Monday morning. The family asked that fans respect their privacy during this trying time. The actor/musician was 73 years old.