With a new sailboat in tow, Dan Risland set out Friday with his three young sons for what was to have been a blissful, windy, spring afternoon on Clearwater Lake in northern Minnesota. But the outing turned deadly when a strong gust of wind caught their sail, capsizing the boat and throwing 2-year-old Jacob, 6-year-old Zech and 8-year-old Isaiah into the frigid lake water.

Of the three boys, only Isaiah survived. On Saturday, he was in critical condition at Children's Hospital of Minneapolis, with his devastated parents by his bedside.

"The kids were his entire life," said Rosie Miles, Risland's sister. "You never saw Danny without his kids."

The loss of the two young lives has rattled residents of the region near Risland's home in tiny Leonard, Minn., population of just 41. In the past decade, a similar incident has happened only once in Clearwater County, the sheriff said on Saturday.

Gadget Soule, Risland's sister-in-law, watched the boys leave with their father, thrilled to take the sailboat out for the first time. "They were all excited to go out and sail with Daddy," she said. "They lived for him, and he lived for them."

Several residents called Friday's accident a tragedy but said they were too emotional to talk. "It's devastating for us as a school and as a community," said Kristil McDonald, principal at Clearbrook-Gonvick Schools, where the two older boys were enrolled. "Everyone knows everyone. We'll all be grieving and dealing with the situation."

Risland was an avid outdoorsman -- from ice fishing in the winter to riding ATVs in the summer. Miles said Risland had bought the sailboat just last week but was licensed and familiar with boats from years of fishing.

The family was sailing on Clearwater Lake, which overlaps Beltrami and Clearwater counties, about 45 minutes northwest of Bemidji. About 3 p.m., strong winds tipped the boat over, Clearwater County Sheriff Mike Erickson said. Risland tried to get ahold of the boys, all wearing life jackets. But he struggled in the wind and waves, and was beginning to get hypothermia.

"He told the oldest one to watch his brothers," Erickson said, "and he swam to shore to get help."

Ice had recently melted off the lake, but by the time authorities got there, the boys had been in the 40-degree water for about an hour, Erickson said.

Efforts to revive Jacob and Zech were unsuccessful, and the boys died of hypothermia.

Isaiah was airlifted to Children's Hospital, where he remained Saturday. His family reported that he opened his eyes but was unable to breathe on his own. "The family is asking for people's prayers at this point," Children's Hospital spokesman Justin Theodotou said.

Hypothermia can happen quickly, depending on factors like a victim's age or weight. According to the Minnesota Department of Natural Resources, after a person has spent 30 minutes in cold water, a body's temperature begins to fall, leading to unconsciousness.

The three little blond brothers were typical rambunctious young boys, unable to sit still unless they were watching "Veggie Tales" together or playing outside with their father, Miles said.

Dan Risland, 31, and the boys' mother, Ruth Risland, 30, of Bemidji, have large extended families in the region. Risland also served as mayor of Leonard for several years. "Everyone in Clearwater County knows Danny," Miles said.

She added that the Rislands are devastated by the accident.

"It was Easter weekend; he wanted to take his kids out on his new boat," Miles said. "He told me, 'I love my boys.'"

Another sister, Theresa Risland, remembered all the fun things she used to do with her nephews. "We would play in the dirt, in the driveway, go to the park or even on the trampoline ... They will always be loved dearly."

Donations can be sent to Dan Risland fund, Country Faith Church, P.O. Box 41, Clearbrook, MN 56634

Staff writer Wendy Lee contributed to this report. Kelly Smith • 612-673-4141; Twitter: @kellystrib