Less than two weeks after America's Got Talent singer Evie Clair experienced a heartbreaking loss, she returned to the show to give a final performance that tugged on everyone's heartstrings. The 13-year-old has been open about her father, Amos Abplanalp, and his battle with cancer — and she paid homage to her dad by singing Louis Armstrong's 1967 classic "What a Wonderful World."

https://www.youtube.com/watch?v=-VWCkpofbro

The AGT audience was captivated by Evie's angelic voice, but they were also deeply invested in her relationship with her dad — which is why it was so heartbreaking when he passed. Just days after she found out that she had been voted through to the AGT finals, Evie took to Instagram to reveal that on Thursday, Sept. 7, her dad passed away.

"This week has been the best and worst week of my life," Evie wrote. "I'm so grateful for the memories I've made with my family in the past year and a half. I'm so grateful for my dad being such a great example of faith and strength. He has endured so much and all that pain has finally come to an end. He is in a place '12 gazillion' times better than this and I know he is so happy there."

"I'll miss you so much, Daddy," she continued. "Thanks for teaching me to love salsa and chicken wings and most of all the Lord. Love you lots."

Evie had been posting regular updates on her father's condition on social media, and last week she posted a photo of her father from his hospital bed on Facebook. "My amazing dad needs prayers and good thoughts tonight, so I'm asking all of you. Thank you, friends," she wrote in the caption.

My amazing dad needs prayers and good thoughts tonight, so I'm asking all of you. Thank you friends.

Posted by Evie Clair on Saturday, September 2, 2017

Amos' condition seemed to get worse over the past few weeks and Evie's mother has documented her husband's cancer battle on her blog, titled Team Amos. She explained that after Amos' health steadily declined, the family came to a group decision to take him off of life support and allow him to go peacefully.

"We watched him take his last breaths as he continued to breathe for about 15 minutes on his own," she wrote. "The children burst into tears but are now at home laughing at old home movies of daddy and remembering our great love for the most wonderful man any of us have ever known."

Before his death, Amos was extremely supportive of his daughter's dream of becoming a singer. Even though he unable to sit in the audience at AGT, that didn't stop him from watching his daughter perform in the live shows. In a video uploaded to Evie's YouTube channel on Aug. 23, Amos watched his baby girl on TV from his hospital bed. "Good luck baby," he said. "I'm sorry I missed it live."

The camera continued to film his reaction to Evie getting voted through into the semifinals and it was extremely emotional — he burst into tears as soon as host Tyra Banks called her name. When she said "I love you, daddy," he blew a kiss at the TV.

During her AGT audition, the Arizona native belted out Christina Perri’s 2011 song “Arms” and she explained that it's a song that she sings to her father as he battles cancer. Amos was diagnosed with Stage 4 cancer about a year ago and he was given a five percent chance of living. “When my dad is having rough days," she said, "I sing him this song to make him feel better and give him comfort and strength to continue fighting."