The anglers had just gotten to the island when they spotted an airplane flying down through the canyon above them. They were close enough to see the pilot. He seemed to be waving at them. They waved back.
The young men—Daryl was 22 and David 23—had started fishing again when the water rapidly rose about six feet. Benson said, “We’ll have to swim out of here!”
Grigg turned and looked upriver to see a 30-foot-high wall of water coming straight at them. He yelled for Benson to jump in and start swimming.
“We started out swimming, but that didn’t work,” Grigg said in a 1977 oral history recorded for Utah State University, Ricks College, and the Idaho State Historical Society. “Then, that was the last time I (saw) David. There were thousands of logs, so I grabbed onto one of them. I didn’t have to swim after that. I just remember looking around. It was unbelievable, everything was tearing everything else up. I couldn’t hardly hear anything because of the noise. Then I saw a couple of houses get wiped out.”
Grigg had no way of knowing that the Teton Dam, which had just finished filling for the first time, had washed out, one side of it collapsing. He rode the debris downstream, getting crushed by logs, about three miles before hanging up on a tree. He was able to work his way into the tree and climb above the roaring water.
Wrapping his arms around the cottonwood tree about 30 feet up, Grigg found a fork he could collapse into. It was hard to get his breath. He went in and out of consciousness, stuck in the tree for what would be at least four hours. Later he learned that he had five broken ribs and a punctured lung.
Describing his chaotic ride to the tree that saved him, Grigg said, “I was right in front of the wave. I could see it grow, the trees coming up, that I’d go right through them and there would be nothing left. Sometimes it really scared me. Some of the logs I was on, they’d get caught on a tree, sit there and stop for a couple of minutes, nearly five minutes, just sit in one place. And you see water tearing up everything all over. The water would raise and then we’d go down the river again. I was climbing over the logs quite a bit, trying to get to shore.”
About his eventual rescue, Grigg said, “I think I was in shock really bad and I think I went out for a while. I woke up, it was getting really late, so I started yelling. I couldn’t see anything. I was scared. Luckily, there was a bunch of people over on the hill there… and they could hear me. So, they brought a boat out.”
Grigg was flown first by helicopter to the St. Anthony hospital, then in another helicopter to the hospital in Idaho Falls, where he spent 10 days recuperating. The body of his friend, David Benson, was found two days after the flood, one of 11 victims of the Teton Dam collapse.