"Then the lights turned upside down, and everything went dark," Nelson said.
The four rescuers, wearing life jackets, were washed downstream. They, too, found trees to grab.
The current "felt like being pulled behind a boat by a ski rope," Schuldt said. His jacket snagged on the boat, adding to the panic. Mahoney told him that if he didn't make it, "You tell Lisa [his fiancée] I love her."
Flashes of lightning lit the eerie scene.
Fritz, a Department of Natural Resources conservation officer, arrived about 2:30 a.m.
His 17-foot flat-bottomed aluminum airboat has an airplane propeller powered by a 350 horsepower engine. The propeller is in a steel cage behind the pilot's seat. The craft can skim over sandbars and debris. But it has no reverse and needs a wide clearance to turn around. The six survivors were clinging to the treetops, Fritz said, in about 15 to 20 feet of water.
"The concern was if a log or branch hits my prop, my prop will explode, and we're dead in the water. And then we're going to sink, because there's no floating in that current," Fritz said.
Despite the risk, the 46-year-old didn't hesitate. "You do what has to be done. Yes, it was a very high-risk rescue in conditions that you don't train in. But anyone else with that kind of equipment and training would have done the same thing."
Fritz operated the airboat, while other rescuers pulled people in, one trip at a time.
"When I looked at those trees, I said a little prayer ... 'God, make sure there's room on the other side of those trees to turn my boat around.' And then we headed into the woods. I was hitting trees and banging off them."
Said Fritz: "The entire time the river is going up and down, it's very turbulent. It was pitch black. And it was raining harder than you've ever seen rain come down. The noise from the river was so loud you could hardly talk."
He had rescued Welch, Dawn Blackburn, and Ernster, then went out a fourth time to get Schuldt and Mahoney, the two remaining firefighters.
"When I got in line to save them, they each pointed to another tree and said, 'Don't get us, get her.' I didn't realize there was another victim from the car. So I drove by them and we pulled another female [Peterson] out of the tree."
He then made a fifth trip to get Schuldt and Mahoney.
"I knew I didn't have enough room to turn around, but you have to go," he said. His boat smashed into the trees, but didn't flip. "Someone above me was helping me out," he said.
They made it safely to shore. It was about 3:30 a.m.
Fritz, a conservation officer for 22 years, said he doesn't consider himself a hero.
"It was a team effort. I was doing the job I was trained to do," he said. "I'm a God-fearing man. Those people had a purpose yet, and I was there to help them. I'm just thankful."