A 22-year-old Lincoln man checked into the hospital, thinking he had the flu. Hours later he was dead, leaving behind a grieving father and many unanswered questions.

Mack Backus' son Bryan was a lucky one. "That was one of the amazing things about him. He would take up he was going to do something and he would do it."

Bryan loved bicycles. His father says his son could get lost anywhere in the country for days, photographing America and all its wonders. When Bryan bought a bike shop at 33rd and B streets, his father says he was happy. Until last Wednesday.

"They had him in the emergency room all wired up and tubed up. We each got to talk to him for a minute or two." Mack's only son checked himself into the hospital with flu-like symptoms. Seven hours later, Bryan was gone.

"I saw two or three of the doctors coming from that direction. I knew, I knew what they were going to say.”

What would you say to your son if you unexpectedly had only a few minutes left with him? That was the challenge a father faced. "He lived a lot in that 22 years. He did so many things, went so many places, had so many friends that he couldn't have done much better with the 22 years he had."

The family says a team of seven doctors worked on Bryan trying to save him in his final moments. No one can explain why Bryan is gone. "I couldn't imagine he could have been well yesterday and die in a day's time,” says Mack.

The family says the Centers for Disease Control and Prevention and the coroner are waiting on toxicology results before being able to determine exactly what happened. That could take several weeks.

Bryan's funeral is set for Saturday.