Joni Sledge, who with her sisters recorded the defining dance anthem “We Are Family,” has died.

The 60-year-old was found dead in her home by a friend in Phoenix, Arizona, on Friday. A cause of death has not been determined. A family statement read,“Numbness fell upon our family. We welcome your prayers as we weep the loss of our sister, mother, aunt, niece and cousin.” Sledge and her sisters Debbie, Kim and Kathy formed the Sister Sledge in 1971, but had their breakout success in 1979 with “We Are Family.” Sledge is survived by an adult son, her sisters and other relatives.