"What went through my mind [was,] 'I hope this doesn't hurt' [and] 'What will death be like?'" Walz said. "I had absolutely NO control of what I was going to smash into. I had to hit that single tree in just the perfect spot to save my life. What are the odds?? To put it in words that someone told me, 'God's angels guided me to the tree. He was there under the tree with his hands open to catch me.'"
Like Walz, Shirley Dygert, 54, a first-time skydiver, thought of her family as she believed she was falling to her death. But her instructor, David Hartsock, 44, who was strapped to her back, had an entirely different series of thoughts going through his head -- how to save both of their lives.
Dygert believes that, in the end, Hartsock sacrificed himself to save her as they spun out of control on that 13,000-foot tandem jump outside Houston on Aug. 1, 2009.
"After we went around three times, we were sort of picking up speed and I was getting dizzy [and] I said, 'I don't know if I could take any more of this, Dave,' and he said, 'I'll be honest with you: We're in trouble,'" Dygert told ABCNews.com. "I thought, 'This is how I'm going to die.' And then I thought I would see my mom. She had already passed. And then, when I thought about my mom I thought about my kids on the ground seeing this. I said, 'Oh God, I don't want my kids to see this.' And then I started praying."
Hartsock, who'd been on more than 800 jumps, said he worked his way through a mental checklist of emergency procedures, but none did the trick.
"The last thing you're going to do is panic," he said. "You panic, you lose your skill. ... Nobody knows how they'll react."
Sandra Levy Ceren, a clinical psychologist in Del Mar, California, who has worked with victims of trauma, said she is not surprised the by varied reactions reported by people who believe they were falling to their deaths.
"I think that there may not be a universal response," she said. "I think it may be the kind of person someone is, the kind of life experiences they may have [that] may have them react in different ways.
"Some people may freeze and not be able to think," she said. "Some people may use their creativity and their ability to be assertive and strong to save themselves."
Or to save others.
As time before impact grew short, Hartsock maneuvered his body so he would hit the ground first. He bore the brunt of the fall, ended up paralyzed and now needs round-the-clock medical care.
"I know how to fall. I know how to take an impact on the ground. I had to protect her," he said. "The only bones I broke, unfortunately, were in my neck. It was a pretty good landing, actually. ... Unfortunately, the bones I broke in my neck left me a quadriplegic."
Dygert, who suffered organ damage and also broke vertebrae in her neck, as well as some ribs and her sternum, vows never to skydive again. But she is telling the story of Hartsock's heroism in hopes of raising money to pay for his care.
"He didn't have to take that fall for me," Dygert said. "I'm hoping that something good comes out of this for David because he has nobody to help him without his mom," Viki, who rarely is able to leave his side.