BOB ABERNETHY, anchor: Each year in the United States there are 29,000 organ transplants. The relationship between donor families and the recipients of their loved one's organs is complex and emotional, involving both gratitude and guilt. Judy Valente reports.

JUDY VALENTE: It's a service that takes place once a year in springtime at Loyola University Medical Center outside Chicago, a nondenominational candle-lighting ceremony to remember those who, in death, donated their organs so others could live. Many who attend are awaiting transplants. Those wearing surgical masks are recent organ recipients. Their immune systems are still weak. Among them, 46-year-old Ben Mazzone, who underwent a double lung transplant last year. In the audience, the Walker family who came to remember 11-year-old Chance, a sensitive, tow-headed boy who was known to give his allowance to the homeless. Chance's parents found him in his bedroom hanging from a bathrobe belt. It might have been suicide, or just a tragic accident, they say.

CONNIE WALKER (Chance's Mother, speaking at service): We thought of how Chance wanted to help people and knew the way that could happen now was to donate his young, healthy organs.

VALENTE: Chance's younger sisters remember him through poetry.

AURORA WALKER (Chance's Sister, reading poem at service): You are my family. Without you I am lonely. So stay with me, even though I am withoutÖ

VALENTE: It is a moment to reflect on the mystery that unites the people who died and those who receive their organs.

MARY MCGILLICUDDY (Social Worker, University of Loyola Medical Center): The question almost always comes up, why me? Why did I survive when someone else had to die? I try to remind them that people are born and people die every single day, and that their living is not directly attached to the fact that another person died. They have been gifted with an organ of someone who died, but that person did not die in order for them to get an organ.

VALENTE: Ben Mazzone, seen here with his twin brother, Pat, had been healthy and active nearly all his life. He considered becoming a priest.

BEN MAZZONE (Organ Recipient): I was more Catholic than the pope. I was so involved in my church. I literally lived at church.

VALENTE: About six years ago, Ben's health began to change dramatically.

Mr. MAZZONE: As I was climbing up the stairs, my mother noticed I was getting winded more and more each time, and she was a little nervous about it, and I just kept thinking it's nothing, don't worry about it. I'm in my mid-30s, late 30s, a little overweight, you know. I'm getting older, not really exercising. It's just that I'm getting old.

VALENTE: Doctors at first thought he had asthma. Mazzone was diagnosed in May 2001 with idiopathic pulmonary fibrosis, a degenerative lung disease.

Mr. MAZZONE: My initial thought was that I'm going to get through this because God's on my side. You know, I've been there for him, he's going to be there for me. But then when I saw the mortality rates and the prognosis and what's going to happen, I got really angry with God. When I was first told by the doctor that I was going to be put on the transplant list, it was complete fear. I just kept picturing myself lying on the operating table, my chest cut open. At some point I wondered, you know, how could God hate me so much? I was not aware that I was that close to dying. They called me and said they had a set of lungs, and we went to the hospital. By the time I got to the hospital, I had passed out.

VALENTE: Doctor Michael Eng was part of Mazzone's surgical team.

Dr. MICHAEL ENG (Surgeon, University of Loyola Medical Center): He was probably as close to death as you could get.

VALENTE: The doctors soon made a terrible discovery. The lungs the hospital had acquired were not suitable for transplant. What transpired then was a series of events Mazzone's physicians describe as nothing short of miraculous. Almost immediately another set of lungs became available.