Dave Costello had survived a cancer scare and was being kept alive by a mechanical heart, but he was so determined to take his wife, Audrey, to a church concert that he wrote "date night" on the calendar one February evening in 2013.

Costello, who suffered from a rare heart disease, had been on the transplant waiting list at the Mayo Clinic in Rochester for more than four years. Complications from his condition had also damaged his kidney, so he knew his chance for a long life were getting slim.

"I knew I had lived a good life and if it was time to go, it was time to go," said Costello, 61.

At the concert, there was talk and music about getting through dire times, and promises of better days ahead. Costello turned to Audrey and said, "I think we're here for a reason."

The Costellos were heading home afterward when they noticed the caller identification on their phone read: "Mayo Clinic."

The message was one they had been waiting for: "We have a heart and a kidney with your name on it."

But it wasn't simply the joyful moment you might expect.

"When we got the call, I knew someone had passed," said Costello. "I had a hard time with the notion that somebody had to die for me to live."

The donor in this case, "Kevin," had apparently spent a career saving lives as a police officer and nurse, and that continued after the automobile collision that killed him and a son. His organ helped save the lives of Costello and 39 others, all because Kevin had signed up to be an organ donor.

Costello had signed up to be a donor by checking the box on his driver's license application in the 1970s, "never knowing I might need a donor myself." Since finding out about his potentially life-threatening illness, Costello has become an avid advocate of the donor program. As a volunteer for Mayo's LifeSource program, he will speak to students at Eagan High School on Thursday on the importance of being an organ donor.

But this time he's not just doing it out of gratitude. His own son, David Jr., is awaiting a liver transplant because of a genetic disease.

"Maybe I had to go through what I went through to be an inspiration to him," Costello said.

Since his own diagnosis, Costello, who is a retired commercial Realtor, estimates he's spoken to thousands of high school students about donating their organs when they die.

"It's not that they are philosophically against it," he said. "Most just don't know much about it, and there aren't a lot of people who want to talk about it."

Costello does, and he does it with the zeal of someone who was told that his life would likely be tragically short and now has little to lose. He also does it with considerable humor.

"I had an uneven heartbeat, and they had to take a piece of my heart to test it," Costello said. "My wife told them she was glad they found something there."

And when she learned he needed both a heart and kidney, "she said she wanted a three-peat, and they should also give me a new brain while they were at it."

Costello also tells students about the time he met the family of his donor. Kevin and his 8-year-old son died in the accident, and his wife and 1-year-old survived.

Costello met them at a picnic for donors and survivors, and the small child reached out to him, almost instinctively.

"We have a picture of him putting his hand on my heart," said Costello. "On his own father's heart."

In the 14 months since the transplant, "I've come to realize just how sweet and precious and fragile life is," said Costello. "Kevin's gift to me is a remarkable thing. I have a better heart now than I did before, a nurse's heart. Now part of my legacy is to spread Kevin's legacy."

jtevlin@startribune.com • 612-673-1702 Follow Jon on Twitter: @jontevlin