Patti LaBelle is "heart broken" over the death of her Labelle bandmate Sarah Dash.

Dash, one-third of the R&B trio, passed away on Monday at the age of 76, and Patti took to Twitter to share a statement about her longtime friend, who she performed with over the weekend.

"We were just on-stage together on Saturday and it was such a powerful and special moment!" she wrote. "Sarah Dash was an awesomely talented, beautiful, and loving soul who blessed my life and the lives of so many others in more ways than I can say. And I could always count on her to have my back! That's who Sarah was... a loyal friend and a voice for those who didn't have one. She was a true giver... always serving, always sharing her talent and her time.

"I am heart broken, as I know all of her loved ones and fans are. But, I know that Sarah's spirit and all that she has given to the world live on! And I pray that her precious memory brings us peace and comfort. Rest in power my dear sister. I love you always!"

Patti co-founded the group with Dash, Nona Hendryx and Cindy Birdsong, and they found success with hits such as Down the Aisle (The Wedding Song), You'll Never Walk Alone, and Over the Rainbow. They renamed the band Labelle in 1971 after Birdsong's departure and hit the mainstream with their U.S. chart-topping hit Lady Marmalade in 1974.

After they split in the late '70s, Dash pursued a solo career, releasing four albums. She also served as a backup singer for the Rolling Stones and Keith Richards' solo project, the X-Pensive Winos, and as a session singer for Nile Rodgers, among others.

The remaining members of Labelle reunited on a number of occasions since the '90s, with them even going on tour and releasing a new album back in 2008.

Dash's cause of death has not yet been disclosed.