Osbourne died on Tuesday at 76, just weeks after he and Black Sabbath performed at their farewell Back to the Beginning concert earlier in July.

Kelly Osbourne is mourning the loss of her father Ozzy following his death on Tuesday, referencing lyrics from Black Sabbath’s “Changes.” Osbourne posted the brief message to her Instagram stories on Thursday afternoon.

In her first comments since his death, Kelly Osbourne posted the opening lyrics from the song on Instagram with a broken heart emoji: "I feel unhappy I am so sad. I lost the best friend I ever had." The father-daughter duo were known for having a close relationship.