Katharine Mcphee's father has died.

The 34-year-old actress doesn't think her heart will ever ''heal'' after her beloved papa Daniel sadly passed away on Monday (16.07.18) morning, but she's determined to make him proud of returning to the stage next week for her role in 'Waitress'.

Alongside a photograph of her and her father, she wrote on her Instagram account: ''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. He was my biggest fan, my biggest champion, always telling me to ''Give em hell kid!''

''He was so kind and caring and made sure we knew how much he loved us. Not sure my heart will ever be the same. I'm so sad he missed my broadway debut.

''But when I return to the stage next week I hope he can watch it in peace and from up above. Thank you to all my friends who've been so loving and supportive these last 48 hours. I love you Papa. I already miss you so much. This hurts. (sic)''

The tragic news comes just days after Katharine told fans that she was going miss last weekend's production of 'Waitress' because of a ''family emergency.''

She tweeted: ''Hey my Waitress fans... I'm so so sorry to inform you I will be out this weekend from the shows. I'm having to fly back to LA right now for a family emergency. It breaks my heart to disappoint anyone. Sending all my love. (sic)''

Daniel's sad passing means that he'll miss Katharine walk down the aisle after she announced earlier this month that she and David Foster were engaged.

She said recently: ''We're very close friends, and we've been friends for a long time. I'm really, really fond of him, and I think he's an incredible person. I've known him since I was 21 years old, you know? He produced my first single. So he's been really good to me. People can say whatever they want.''