The mother of Wynonna and Ashley Judd died of undisclosed causes.

Naomi Judd, the singer known for her Grammy-winning work as half of country music duo the Judds, and the mother of Ashley and Wynonna Judd, has died. She was 76.

Judd died Saturday outside Nashville, her representative confirmed to EW. Her daughters also announced her death in a statement to the Associated Press.

"Today we sisters experienced a tragedy. We lost our beautiful mother to the disease of mental illness," the statement said. "We are shattered. We are navigating profound grief and know that as we loved her, she was loved by her public. We are in unknown territory."

Further details on Judd's cause of death were not immediately available.

Judd rose to fame as half of a singing duo with her daughter Wynonna, scoring 14 number-one hits on the country music charts between 1983 and 1991. They disbanded that year after Naomi was diagnosed with hepatitis, but reunited several times for special performances and multiple reunion tours. Just this month, the duo reunited again at the CMT Music Awards for their first TV performance in 20 years, and another tour, billed as The Final Tour, was slated to begin this September. The Judds are also set to be inducted into the Country Music Hall of Fame next month.

Naomi Judd in 2018
Naomi Judd in 2018
| Credit: Debby Wong/Shutterstock

Born Diana Ellen Judd in 1946, Naomi Judd grew up in a middle-class family in Ashland, Ky. She eloped with her first husband, Michael Ciminella, and gave birth to Wynonna (born Christina Claire Ciminella) when she was 18 years old. They had another daughter, Ashley, before divorcing in 1972, leaving Naomi to raise the girls as a single mother.

Naomi and Wynonna began singing together while the elder Judd was working as a nurse; after struggling to get Nashville's attention, Judd reportedly secured a record contract through a producer whose child she had nursed. The Judds released their first EP in 1984, followed by six albums over the next seven years. They won five Grammys for Best Country Performance by a Duo or Group With Vocal for such hits as "Mama He's Crazy" and "Love Can Build a Bridge."

"These Kentuckians modernized Appalachian front-porch singing with folk, country, blues, jazz, rock, and pop delivered with glove-tight harmony," Alanna Nash wrote in an EW review of the Judds' discography in 1992, adding that their debut album, Why Not Me, "stood out on commercial country radio like a new Caddy on a road with battered pickups."

The mother and daughter's relationship would sometimes grow strained — at times, they went without speaking to each other — but they would always come back together, and appeared to be on good terms at the time of Naomi's passing.

"There's so much stuff that gets entangled in the personal stuff, and you take it wrong, and you get upset, and then it gets bigger and worse, and it can really fester and become something. That's absolutely not supposed to be," the elder Judd told PEOPLE last year.

In addition to her daughters, Judd is survived by her husband, Larry Strickland, a singer who formerly sang backup for Elvis Presley.

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