Sad news to report from the music world. Joni Sledge, the second eldest sister in the Philadelphia girl group Sister Sledge, has passed away at home in Phoenix, Ariz., on Friday afternoon (March 10). The cause of death is unknown at this time. She was 60 years old.

A statement (via Billboard) from the family reads:

Yesterday, numbness fell upon our family. Pray for us as we weep for the loss of our sister, mother, aunt, niece and cousin Joni Sledge. We thank you for privacy as we hurt for her presence, but also for embracing her radiance and the sincerity with which she loved life.”

Sister Sledge, which consists of sisters Kim, Debbie, Kathy and the now late Joni Sledge, was formed in 1971 and went on to record such memorable songs as "We Are Family," "He's the Greatest Dancer," "Frankie" and more. According to Billboard, their 1979 Grammy-nominated anthem "We Are Family," peaked at No. 2 on the Hot 100 chart and reached the upper echelons of the R&B and disco charts as well. The album of the same name reached No. 3 on the Billboard 200 tally.

Upon hearing the news of Joni’s death, legendary musician Nile Rodgers, who produced “We Are Family” and many of their classic hits, paid tribute to her on his Twitter account. “My heartfelt condolences to your family because they are my family too. We did something pretty amazing together,” he tweeted.

Joni Sledge leaves behind her son, Thaddeus, and sisters Debbie, Kim and Kathy in mourning. May she rest in peace.

Watch Sister Sledge's "We Are Family" Video

Watch Nile Rodgers Talk About Producing Sister Sledge's "We Are Family"