Margaret Smith, 63, was taken to Vanderbilt University Medical Center because of rapidly declining health. She was waiting for a liver transplant, but doctors said health was too poor to survive the operation, WTVF reported.
As she lay in the hospital her nurse, Olivia Neufelder, comforted Ms Smith while her anesthetic wore off by singing her favourite song to her, "Dancing in the Sky" by Dani and Lizzy.
Smith's daughter, Megan, shared the video on Facebook over the weekend, saying Nuefelder sat with her mother for hours and "sang a very special song to my sweet mother to comfort her".
"Words can't depict the thankfulness and love we feel for nurture Olivia who mother calls her blessed messenger!" Both Smith and Neufelder were overcome with emotion during the clip.
"Your devotion to your patients is past any that I have seen, you genuinely are a light emission and I can't thank you enough for the care and empathy and cherish you shared for my mom".
Smith died Wednesday in the Cookeville nursing home. "God bless you Olivia!"
The video, which was taken on October 12, garnered more than 3.6 million views by Friday afternoon. Smith wrote in the post.
Neufelder is touched by the response to the video and said it's been a life-changing experience.
Neufelder told a local radio station that knowing "she will be dancing in the heavens and singing with the angels helps me find peace during this somber time".
"Your dedication to your patients is beyond any that I have seen", Megan Smith wrote in a message directed toward Neufelder.
A gofundme account has been set up to help with funeral expenses.