The number one song “See You Again” from the blockbuster film “Furious 7” has touched the hearts of millions of listeners and moviegoers worldwide. But for Chester County native Bill Cerullo, the haunting words and melody are especially personal because the song is about his son Vail.

“The last four and a half weeks have been emotionally draining but also very energizing,”Cerullo said.

Vail Cerullo grew up in Elverson, Pennsylvania. He became friends with singer-songwriter Charlie Puth when they attended the Berklee College of Music in Boston together. Then tragedy struck in June of 2012 when Vail was killed in a motorcycle accident. He was only 20-years-old.

During the funeral service at Vail’s Alma Mater the Hill School in Pottstown, Puth made a promise to his friend’s father.

“Someday Mr. Cerullo I’m going to write a song for Vail,” Puth said.

A few years later, Puth got the chance to do just that when he was hired to write "See You Again," the theme song for “Furious 7" which in addition to being inspired by Vail also pays tribute to the late actor Paul Walker. The hit song by hip hop star Wiz Khalifa which features vocals and piano by Puth became an international success, reaching number one on the Billboard in 94 countries.

Cerullo told NBC10 the second verse of the song is what touched him the most.

“He talks about all the memories that will lead him home,” Cerullo said.

Cerullo says the song “Home’ by Michael Buble was his son’s favorite. It was also the song Puth sang at his funeral.

“There’s no doubt that he put the word “home” in that song because of that,” Cerullo said.

Cerullo still has the text that Puth sent him after the song was released.

“My gift to you Bill Dawg,” Puth wrote. “We are celebrating Vail every day. He is the reason this is happening.”