NEW YORK (CBSNewYork) — One Long Island man’s selfless generosity has helped dozens of people.

Gavin Charrette’s mother, Barbara Cinicke, and sister, Rebecca, say he was a happy young man.

“Just one of the happiest kids you’ll ever meet. Still a kid at 29. He just looked at life as just, to enjoy it, he just wanted to enjoy life,” Cinicke said. “He was never angry at anyone. He was never sad.”

“He was my best friend,” Rebecca Charrette said. “Always cheered me up. We would make fun of our parents together.”

On Dec. 4, Gavin was struck by a car while walking on Sunrise Highway. Several days later, doctors said his brain had stopped functioning.

“My baby boy, I don’t know what I will do without him,” said his father, Lawrence Charrette. “I just miss him so much. He was everybody’s friend. Sorry, I just miss him so much.”

What Gavin’s mother and father didn’t know at first was that he had recently signed up to be an organ donor.

“I didn’t know about it, but my niece said that he came to her, too, and said, ‘I just got my ID, and I signed up. I’m going to be an organ donor,” Barbara Charrette explained. “So he was very excited and aware of checking that box.”

So his family honored his wishes to be an organ donor, and more. He helped nearly 50 people with liver, heart, lungs, kidneys, skin, bone and corneas.

The story took a strange turn, however, when his family got to meet one of the lives he saved. Maria Langone had been on dialysis, waiting for a kidney for three years. And in a strange coincidence, it turns out Langone and Gavin’s mother had actually known each other briefly as teenagers.

Live on New York connected Cinicke and Langone. Blood and tissue types matched, and Langone got one of Gavin’s kidneys. The surgery took place at Recanati Miller Transplantation Institute at Mount Sinai Health System.

“There are no words,” Langone told CBS2’s Dr. Max Gomez. “It’s a flood of emotion. How do you say ‘thank you?’ How do you say, ‘I’m sorry for your loss’ without being overwhelmed with happiness for the renewal of life?”

“Gavin saved a lot of people’s lives. There are about 125,000 people waiting for organ transplants in the United States, over 100,000 of them waiting for a kidney. And the harsh reality is that most of them will never get a transplant,” said Dr. Sander Florman, Director of the Recanati Miller Transplantation Institute. “They will die before receiving their transplant. So Gavin saved a lot of lives.”

“Surgery went beautifully,” said Dr. Susan Lerner, who performed the transplant. “She is doing beautifully. She is going to be ready to go back to work and is doing great with her life.”

“They saved my life,” Langone said. “They gave me a second chance at life.”

Seeing Langone lets Gavin’s family knows he lives on.

“It’s bittersweet. I want my son to be here. But if he can’t, you know that somebody else can be,” Barbara Charette said.