The Pointer Sisters singer Bonnie Pointer has died aged 69.
Her sister and fellow singer Anita revealed the late star died on Monday in an outpouring of grief.
Her cause of death has yet to be made public.
Anita urged her fans for their prayers while she mourned her sister's death with her family.
In a statement, she said: "It is with great sadness that I have to announce to the fans of The Pointer Sisters that my sister, Bonnie, died this morning.
"Our family is devastated, on behalf of my siblings and I and the entire Pointer family, we ask for your prayers at this time."
The Pointer Sisters included siblings Bonnie, Anita, June and Ruth.
They soared to success in the 1970s after they formed in Oakland, California.
In a personal tribute, her sister Anita hailed Bonnie as her best friend and someone she spoke to every day.
The singer insisted The Pointer Sisters would never have happened without Bonnie.
She added: "Bonnie was my best friend and we talked every day, we never had a fight in our life, I already miss her and I will see her again one day.
"The Pointer Sisters would never have happened had it not been for Bonnie."
The girl group were behind chart-topping tracks Jump (For My Love) and I'm So Excited.
Their glowing success saw the group pick up three Grammy Awards during their sky-rocketing career.
Memorably, their fame was immortalised with a star on the Hollywood Walk of Fame in 1994.
Bonnie used her fame as a springboard to launch her solo career when she left the group in 1977.
She has been survived by her brothers Aaron and Fritz, as well as sisters Ruth and Anita, a representative said.
