A video of a nurse at the Vanderbilt University Medical Center, Tennessee, comforting a dying woman by singing her favourite song is going viral on social media.

Margaret Smith, 63, was taken to Vanderbilt University Medical Center because of her rapidly declining health. She was suffering from liver cancer for about a year and doctors said she was too sick to survive a transplant.

Olivia Neufelder, a nurse at the facility, did her best to comfort Smith by singing her favorite song "Dancing in the Sky" by Dani and Lizzy.

Smith's daughter posted the video on Facebook, which has received more than 3.4 million views and has been shared 64,725 times so far.

"Words cannot describe the appreciation and love we feel for nurse Olivia, who Mom calls her angel," Megan Smith wrote on her Facebook.

She said that the nurse sat with her mother for hours as her anesthesia wore off.

"Your dedication to your patients is beyond any that I have seen," she added. "You truly are a beam of light and I cannot thank you enough for the compassion and care and love you shared for my mother."

Smith was moved to a nursing home in Cookeville, Tennessee where she passed away on Wednesday (25 October).

Following Smith's death, Nuefelder spoke with radio station 1010 WINS about her life-changing experience. Nuefelder said she is glad she was able to provide comfort to Smith in her last days.

"There was almost a sense of peace knowing that it was her favorite song and she did tell me it's the song she wants played at her funeral," Neufelder told WFTV.

"She didn't feel like a patient at that time. I wanted her to know that she was loved even if her family wasn't able to be there."

"Knowing that she will be dancing in the heavens and singing with the angels helps me find peace during this somber time," she said.

"This experience has challenged me in many ways."