Kelly Osbourne is mourning the death of her dad and rock legend Ozzy. On Thursday, the musician and daughter of the Black Sabbath frontman returned to social media for the first time, using the opening line to “Changes.” “I feel unhappy,” she wrote. “I am so sad. I lost the best friend I ever had.”

Black Sabbath singer Ozzy Osbourne's sisters recall their final interactions before his death at 76, noting he was frail but still joking before a farewell performance in England.

Osbourne has tragically passed away at the age of 76—just weeks after it was revealed that he was set to quit his residence in the U.S.