That's what killed the truck's engine. He tried to start the truck once, couldn't, put it in park and got out.
He yelled at Meyer and Olson.
"Get out of the truck. Get out of the truck. It's dead."
Keller isn't yelling these days. It's a whisper mixed with grit when he talks, when he rasps -- the result of having a tube down his throat for weeks.
He was on a respirator for 31/2 weeks. But it came out just in time.
He wanted to be able to speak on May 1, at least. That was his first wedding anniversary and he wanted to tell Michelle, who has stayed with him the entire time, "Happy anniversary."
He got his wish. On April 30, they took him off the respirator.
He was too weak to get out of bed. The anniversary celebration amounted to just this: "We celebrated (the anniversary) by telling each other we loved each other," he said in a recent interview.
The doctors told Michelle that her husband would probably lose the tips of his fingers, his nose and ears -- the parts of him that were black.
But then came pneumonia and strep throat, which became kind of a blessing in disguise, because it meant that the skin grafting would have to wait. "No cutting," Keller said. While he recuperated from those illnesses, the tips began healing -- so he still has them.
It's when he wakes up that he feels the most pain -- in his joints and fingers -- until he can get his dose of pain medication.
From his elbows to his fingertips, it's new skin, kind of. It's all his -- transferred from other places.
Paper-thin sheets of skin from his thighs are now the new skin covers for his hands.
A sheet of skin from most of his back was used to cover his arms.
Dr. William Mohr, the burn center's director, has been a physician since 1991 and has specialized in burn patients since 1996.
"His hands are about the worst I've seen that did not require some type of amputation," he said.
He said most people are fortunate enough to burn just the backs of their hands. Keller's were burned on both sides, making the skin grafting harder, too, as there wasn't unburned skin to tack the skin grafts onto.
But Mohr said Keller is the model patient. Mohr said he has had patients whose skin grafts were beautiful but because they weren't as dedicated to their therapy and had spouses who did too much for them, they ended up with hands that can't do much of anything. They even have difficulty feeding themselves.
"(Mark's) success is a tribute to his hard work with the occupational therapist," Mohr said.
"He is motivated. He doesn't complain. If he's asked to do something, it's not questioned," Mohr said.
And then there's Michelle Keller.
Mohr has had patients, even children, whose parents only occasionally, if at all, come around.
"Their only family becomes us," he said.
"As far as families go, there aren't too many families that are as dedicated as Michelle," Mohr said.
Very soon, the plan is to move Mark Keller to a local hotel and have him come to the burn center during the day -- a step toward home.
Keller trembles when he tries to use his arms and hands, which have some seams like a patchwork quilt in places, where the grafted skin has been stapled in place. But he said the shaking isn't about fatigue as much as it's about the new skin on his arms and hands not having stretched out enough. He shakes as he tries to reach in ways the skin won't go.
The new skin took except for on the ring finger of his right hand.
"It turned to mush," he said.
That finger had to be redone with more new skin from his thigh.
He has a cast on his left hand, except during therapy, to keep those fingers straight. His right hand, where skin grafting hasn't worked as well, has a glove on it to minimize scarring.
In addition to that, more tinkering had to be done to help his face. His burned facial skin had tightened up so much that his lower lids began drooping and then were starting to turn inside out. He was having trouble closing his right eye because of it.