Katharine McPhee's beloved father has died—just weeks after her shock engagement to David Foster.

In a heartbreaking Instagram post, the Waitress star paid respects to her dad, Daniel, and voiced her sadness over his sudden passing.

"I can't believe I'm even writing this.... But it is with heavy heart that I share that my sweet sweet Papa left this earth yesterday morning. We as a family are completely heartbroken and devastated," she wrote, along with two photos of the two together.