Joni Sledge, a founding member of the popular R&B group Sister Sledge, was found dead Friday in her home in Phoenix, Arizona, according to publicist Biff Warren.

She was 60 years old.

The cause of death is unknown at this time, but Warren told CNN that Sledge was not sick at the time of her passing.

The news came as a shocking tragedy to those close to her.

“Yesterday, numbness fell upon our family. We are saddened to inform you that our dear sister, mother, aunt, niece and cousin, Joni passed away yesterday,” reads a statement on the band’s Facebook page.

It adds:

“Please pray for us as we weep for this loss. We do know that she is now eternally with Our Lord.”

Along with siblings Debbie, Kim and Kathy, Joni formed the Sister Sledge in 1971.

The group was based out of Philadelphia, yet struggled for years before finding success.

The group is likely best remembered for the 1979 dance anthem “We Are Family,” along with such hits as “He’s the Greatest Dancer” and “My Guy.”

Speaking to The Guardian last year, Joni said the following of the group’s early years:

“The four of us had been in the music business for eight years and we were frustrated. We were saying: ‘Well, maybe we should go to college and just become lawyers or something other than music, because it really is tough.'”

But the popularity of “We Are Family,” considered to be a female empowerment track that preached unity, changed everything.

The song was nominated for a Grammy and the album on which one could listen to it sold more than one million copies.

It peaked at number-two on the Hot 100 and topped the R&B and disco charts.

At one point, years later, Kathy left the group for a solo career, but the trio of sisters continued to play concerts and record, including a performance for Pope Francis in 2015.

They last took the stage together in October and were scheduled to perform a show on March 18; a series of European performances was also on tap.

Joni Sledge is survived by an adult son, her sisters and other family members.

May she rest in peace.

Scroll around below for a look at other well-known singers, actors and actresses who have passed away in 2017.

We send our condolences to their loved ones.