Dustin, Devin and Danielle Wahl attempted to be the first three siblings to swim the English Channel simultaneously. Devin and Danielle completed the swim, but Dustin fell short. (Courtesy of DeeAnna Wahl)

In the end, the odds were too much for the three Wahls.

Devin and Danielle Wahl completed their English Channel swim Sunday. The 21-mile crossing in 64-degree water was more harrowing and painful than they expected. Their younger brother Dustin was forced to quit 13 miles in, overcome with cramps and nausea.

The goal of being the first three siblings to swim the Channel simultaneously—statistically, they had about a one-in-eight chance of success—remained elusive. But their sense of accomplishment was huge.

“I’ve done a lot of endurance events, but as far as the mental aspect is concerned, this was by far the hardest challenge I’ve faced,” said Devin, 24, who has completed two Ironman-distance triathlons. “All the stories are true.”

His younger sister, Danielle, 21, swam the Channel last year, recording the season’s fastest time by an American. This year it was harder and took an hour longer.

Dustin, Danielle and Devin Wahl in Loveland, Colorado. (Courtesy of Devin Wahl)

“I wasn’t feeling particularly great, but I got the job done, so there’s nothing to complain about,” she said.

Devin finished in 11 hours flat; his sister was 13 minutes faster.

Dustin, 19, was philosophical, and generous in his praise of his older brother and sister.

“It was an attempt. It’s brutal out there,” he said. “I’d rather do something great and fail than do nothing and succeed.”

As in her previous Channel swim, Danielle considered quitting this time, too.

“I had the e-mail all written in my head — ‘I’m so sorry I didn’t make it . . . ’ I knew exactly what I was going to say to everyone.”

In fact, she almost didn’t make it. Halfway through her seventh hour of swimming, she lost consciousness for about 10 seconds, a phenomenon that’s been seen in other people doing marathon swims in cold water. As she floated facedown in the water, her father, on the boat shadowing her, tore off his clothes and prepared to jump in to rescue her. Before he could, she came to and resumed swimming faster than before.

She made landfall at a cliff. She couldn’t climb ashore, so she tagged France and swam back to the boat.

As with many Channel swims, the Walls’ event was a charitable effort as well as an athletic one. They are raising money for research on Alzheimer’s disease, a form of dementia that afflicted one of their grandparents and an uncle. They’ve collected about $15,000 so far.

“I was thinking about the people with Alzheimer’s disease and what they and their families are going through,” Devin said. “I can have 11 hours of pain. Some of them have years of pain.”

Devin lives in Baltimore and works in a laboratory at the National Institute on Aging there. His brother and sister (and two other siblings) and their parents live in Colorado Springs.

Under the rules set by the two organizations that certify English Channel crossings, swimmers wear only bathing suits and caps. Wet suits aren’t allowed, and the athletes can’t touch the boats accompanying them or the people on them.

Scheduled for July 22, the swim was repeatedly delayed because of bad weather. Each of the siblings’ swims had its own drama.

Dustin said he “really hit the wall” about three hours into the crossing. He’d swallowed a lot of seawater, was nauseated, had been stung by a jellyfish and had cramps from the cold.

The rules allow a “support swimmer” to enter the water once an hour for encouragement (but no contact). Dustin’s assistant advised him how to stretch his aching limbs. But in the end, it wasn’t enough.

Seven hours in, Devin was in a confused state and wanted to quit.

“I went over to the boat. I was basically bonking,” he recalled the next day. “My mom said, ‘What are you doing? Keep going.’ I drank some Coca-Cola for the instant sugar boost and somehow just kept going.”

Devin did make it onto land, but he needed a guide.

For the last hour of his swim, he swapped out his regular goggles for a pair with a light stick attached so he would be visible in the dark. The goggles were dirty and he could barely see through them.

On the boat was a man named Richard who had twice attempted the Channel and failed. (He had seen a posting the siblings had put on a Web site seeking crew members for the three boats.)

Richard, who had been shouting encouragement all day, jumped into the water as Devin became disoriented several hundred yards from land. Swimming, he led him in.

“We both stood on the shore together,” Devin said. “We had just become so close. I gave him a big hug.”

The funny thing is, he never learned Richard’s last name.