Nebraska Medicine, a medicine clinic in the US, allowed an organ donor's mother to hear her son's heart beating inside another man's chest for the first time.
Lisa Swanson and her son Shelby Schulz met Terry Hopper for the very first time, the man their relative's heart saved.
The donor was Levi Schulz -- Ms Swanson's 18-year-old son and Shelby's twin brother, who was involved in a car accident in 2012.
He was kept on life support in order to allow his organs to be donated.
"I get happiness and sadness all at the same time. Sad that my son is not here but happy that he was able to help Terry," says Ms Swanson.
Nebraska Medicine told Reuters that Mr Hopper was put on the transplant list in October 2012 and received his new heart after a 52-day wait.