Rihanna is mourning the loss of her grandmother Clara "Dolly" Braithwaite, who has died following a battle with cancer, Contact Music reports. The R&B superstar expressed her grief via Twitter, offering a possible explanation for the disastrous performance she gave Saturday (June 30) at the Peace & Love Festival in Sweden.

"Goodbye #grangranDolly get your beauty rest until I see you," Rihanna tweeted, adding, "#grangranDolly that is all."

Ri went on to post a series of instagram tribute photos, and following a condolence tweet from Chris Brown's mother and manager, Joyce Hawkins, the Bajan beauty sent some love right back to her ex's mom.

"@mombreezy thank you!" Rihanna tweeted. "Love You Angel."

News of Dolly's passing surfaced after Rihanna angered fans in Sweden by taking the stage 45 minutes late and mistakenly dedicating a cover of Bob Marley's "Redemption Song" to Norway. Figuring she was drunk, some concertgoers even walked out.

That she seemed distracted is, in hindsight, not surprising: Rihanna was famously close to her grandmother, and last month, she spent Father's Day visiting Dolly in her New York hospital room. Afterward, she tweeted a series of photos and wrote, "My heart smiled and cried all at once."

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