NEW YORK (PIX11) -- Family and friends said FDNY Firefighter Billy Moon had the biggest heart. Thursday night, his widow, two young children and parents got to hear that heart again in the chest of the man who received it.

Moon died after falling twenty feet during a training exercise in Brooklyn in December of 2022. Kristina Moon transferred Billy Moon to LiveOnNY's Donor Care Unit at NYU Langone Health. Five of Billy Moon's organs have been transplanted into recipients.  

Thursday night, Moon's family got to meet 63-year-old Richard Grehl. He received Moon's heart just ten days after going on the donor list.

"I'm Rich, in more ways than one, thank you so much," he said when meeting Moon's widow.

Kristina Moon used a stethoscope to hear her husband's heart in Grehl.

"He was passionate. The passion comes from the heart, so to hear that heart is still beating is very emotional," Kristina Moon said.

Colin Moon, 9, sobbed after hearing his father's heart again.

"It feels like, when I would take naps right next to my dad, and it feels like I was right next to him because when I was doing it, I heard his heart beat," he said.

LiveOnNY President and CEO Leonard Achan asks everyone to consider signing up as an organ donor. You can do it through the state DMV or the National Organ Donor Registry.

"This remarkable story of heroism and hope serves as a poignant reminder of the profound legacy of organ donation left by Firefighter Moon, who, even in his untimely passing, continues to make a difference and save lives," Achan said.

Organ donors and recipients are anonymous but can choose to meet with the assistance of programs like LiveOnNY.