A four-year-old boy in South Carolina has become a sensation after a photo of him with Santa Claus praying in Las Vegas for a sick baby he did not even know was posted on Facebook.

Prestyn Barnette was at the Dutch Square Mall in Columbia, South Carolina a week ago when he chanced upon a Santa Claus, according to Fox News and WIS-TV.

He asked Santa for a toy train and also prayers for Baby Knox, a two-month-old who is in a hospital in Las Vegas and being kept alive through a respirator.

Prestyn does not know Baby Knox or his family. He only learned about him through his grandmother's Facebook prayer group.

"Santa said we will pray now and he got down and prayed," the grandmother Robin Sharpe told WIS-TV. "There were many bystanders there that day. They just stood some of them, just bowed their head and prayed."

Prestyn's aunt, Rebekah Lauren Sharpe, took a photo of the boy praying with Santa and it became viral after she posted it on Facebook.

Baby Knox Joseph's family appealed for prayers on Facebook after the baby was found by his father not responding to touch in his crib on Nov. 30. The baby stopped breathing.

The dad, Carl, performed CPR on the baby and was able to revive him. The baby was then taken to a local hospital but had not regained consciousness as of Monday.

A GoFundMe page has been set up by friends to help the family with the hospital expenses.

"We are so thankful for them, and feel as if God is using so many people to be a blessing to our family. We are not certain what insurance is going to cover now or later, we are working with a case manager to help figure this out as it gets closer to time to go home with Knox. I (Carl) am currently on unpaid medical leave (FMLA) for up to three months," Baby Knox's dad wrote on the fundraising page.

Carl said they "are seriously preparing to transition home."

"Baby Knox has been taking occasional breaths on his own, and while the staff continues to remind us that they are 'ineffective' any sort of change is encouraging to see. We have been praying for a miracle for Knox, and while we fully believe that God has already done miracles for Knox, we are hanging on, begging Him to send His healing to our baby boy," he wrote.