Mother hears late son's heart beating, 4-years after donating his organs

(INSIDE EDITION)- This Kentucky mother lost her son four years ago, but she was able to hear his heartbeat for the first time after meeting the Iowa man who received it in a transplant.

In an emotional reunion, Dawn Grace of Crofton held her face against the chest of Joseph Hansen, 55, to hear her son's heartbeat for the first time since he died in 2012.

"It was very scary but exciting," she said in a Nebraska Medicine press conference Friday. "I think Calen is looking down on me, and he's proud of what his momma did."

During the press conference, Dawn Grace explained her son died when he was 14 years old after he accidentally shot himself with a gun.

"It was a defective gun," Grace explained. "With his 14-year-old mind, he didn't think it worked."

On the way to the hospital, Grace said she remembered paramedics asking if she wanted to donate her son's organs. "I was very angry," she said.

But she reconsidered, and decided that donating Calen's organs was ultimately what he would have wanted.

Little did she know, her decision changed the life of Hansen, of Council Bluffs, Iowa.

"I wasn't able to do things people my age was doing," Hansen said.

He said he felt himself "dragging a little bit more and more," before he started having heart attacks.

Finally, Hansen was diagnosed with hypertrophic cardiomyopathy. His heart muscles were thicker than normal, which made it difficult to pump blood to the rest of his body.

When he received the transplant, Hansen immediately reached out to the family of the donor.

The Grace family sent a letter back, including Calen's final school portrait from 2012, which Hansen now carries in the front fold of his wallet.

"All I could think about was the young man," he said during the press conference. "That's all I could think about."