This is one of the most heartbreaking and emotional things you will ever see.

Eric Schmitt-Matzen, who plays Santa Claus in Knoxville, Tenn. has gone viral for sharing this devastating story of how a terminally ill child died in his arms while he visited with him in the hospital.

Schmitt-Matze was summoned to a hospital to see the unidentified boy who wanted to see Santa Claus about six weeks ago. The boy's mother gave Schmitt-Matze a toy from the show Paw Patrol to give to the child.

Schmitt-Matze asked everyone to clear out of the room to decrease the chances he would start weeping. He then described the encounter, which should reduce anyone to tears. Watch and listen as a clearly distraught Schmitt-Matze describes what happened just before the boy died.

Schmitt-Matze does have one regret. "I'd trade places with the kid...the kid would have been in his mom's arms, not mine," he said. "You know, you can't control that."

UPDATE: It turns out that some of this story's details may not be as accurate as initially reported. Read a follow-up here.