Lucinda Williams posted a moving tribute to the late Tom Petty on Facebook on Friday (Oct. 6), just a few days after the music icon's death on Oct. 2. Williams had opened for Petty at his Hollywood Bowl shows during the last week of September, days before he passed away, and was part of Petty's ASCAP Songwriters’ Hall of Fame induction and MusicCares Person of the Year ceremony earlier this year.

"I have been heartbroken since I first heard the news. I couldn’t believe it was real. It just couldn’t be," Williams writes alongside a photo of herself and Petty at the Hollywood Bowl. "It has taken me a week of tears to be able to sit down and write these words."

In her Facebook post, Williams recounts her relationship with Petty over the years. Their friendship began in 1999, when she opened for him.

"After a couple of shows, he could see that the audience wasn’t exactly being receptive, and so one night, much to my surprise, he went out and introduced me before the show, telling the audience they needed to listen." Williams shares. "That says so much about who he was -- and who he was to me."

After offering her heartfelt sympathy to Petty's surviving family and friends, Williams thanks Petty for his role in her life. She closes with an appropriate sendoff for the rock icon: "You were born a rebel, and it’s okay to go home now."

According to a statement from a Petty family spokesperson, Petty suffered a heart attack at his Malibu, Calif., home “in the early hours of [Monday] morning” (quote via Ultimate Classic Rock). He was taken to UCLA Medical Center, the statement continues, “but could not be revived.” He died at 8:40PM PT, “surrounded, by family, his bandmates and friends.”

Country Artists Mourn Tom Petty