A Texas man has a new chance at life following a successful kidney transplant, even as he mourns the death of his donor -- his own 22-year-old son.

Nate Castillo, of Ennis, was awaiting a new kidney after two decades of diabetes caused his own organs to fail. According to KDFW-TV, Castillo was on the waiting list when his family suffered a tragedy June 30.

Castillo’s son, Symon Castillo, was out with friends in Fort Worth when he fell off of a ledge in a “freak accident,” his family told the news station. He suffered a traumatic brain injury and died on July 5.

Symon’s aunt, Monica Castillo, said that a piece of the family is gone.

“He was an amazing young man who just loved life,” Castillo said Thursday.

Symon, who family members described as giving from a young age, decided at age 18 to leave a piece of himself behind by becoming an organ donor.

"He was going to be somebody's hero," his sister, Tatum Gallardo, told WFAA in Dallas.

No one anticipated that one of the lives he might someday save would be his father’s. Testing at the hospital showed that Symon’s kidney was a match for Nate Castillo.

Castillo underwent a successful transplant in Dallas, even as his family was planning his son's funeral. WFAA reported that he was discharged from the hospital hours before the service.

"I don't even know how to explain the feelings that are there," Castillo told the news station. "I didn't think he would be saving me instead of burying me."

Symon’s mother, Emma Castillo, told WFAA that a part of her is jealous.

“He has a part of him,” she said.

Symon’s other kidney and his heart were donated to patients in Houston.

An obituary in the Waxahachie Daily Light described Symon as the "light of (his family's) life."

"Symon has the biggest dimples, the most beautiful smile, the brightest eyes, the most infectious personality, the kindest, most giving spirit and the biggest, biggest heart," the obituary read. "Symon is a true, genuine, sincere soul who cares for all people. He is the true definition of humble and that is what he wants to instill in everyone he meets."

One of his loves was softball, which he played with his father just two days before his accident, Nate Castillo told WFAA. It was also the last time the father and son spoke.

“I actually got to say, ‘I love you,’” Nate Castillo said.