BLACK, Mo. — A Millstadt man and his two young sons who died while hiking in the cold on a remote southeastern Missouri trail were experienced with the outdoors -- they just had a freak accident, police and a family member said.

David Decareaux, 36, was pronounced dead Sunday morning near Black, Mo., in Reynolds County, where he had been staying at the Brushy Creek Lodge with his wife, Sarah, and five children -- ages 12, 10, 8, 4 and 2.

He and two of those children, 10-year-old Dominic and 8-year-old Grant, had been hiking with their 4-month-old yellow Labrador retriever Saturday when they got lost, according to Reynolds County Sheriff's Department. They were found Sunday morning.

The boys died Sunday afternoon at a hospital in Ellington, Mo.Their father had died at the scene. The dog was found near the boys and their father, and survived.

"Dave was a good family man and a good father and husband," his father-in-law, Keith Hartrum of Waterloo, said. "They just got caught in an unfortunate situation."

Reynolds County Sheriff Tom Volner said Decareaux didn't realize that weather conditions were deteriorating so rapidly. The father, who took his family on a vacation in celebration of the couple's wedding anniversary, was spotted by a motorist who offered a ride back, but Decareaux turned it down.

"There was a passerby who saw them at 2 p.m. (Saturday) at Sutton's Bluff, which was their destination," Volner said. "It had started to rain and the driver offered them a ride back to the lodge. Mr. Decareaux said it wasn't far back to camp and that they would be all right. They should have been able to make it back to the lodge well before dark."

Volner said the mistake that cost Decareaux and his boys their lives was tragically simple: They missed their turn on the trail that led to the lodge, which is about five miles along the Ozark Trail from the bluff. They ended up disoriented after the weather worsened as the sun went down. Rain made the trail nearly impassible by foot and caused flash flooding in the area. Meanwhile temperatures dropped from the 60s into the 20s.

Volner said all three died of hypothermia, and no autopsies were planned.

Neighbor Eric Merz said Decareaux and his family were avid hikers and they were experienced and physically fit.

"I talked to (David) about hiking a lot," Merz said. "I like to hike in Colorado and I told him that he really needed to check out the hiking there. His boys loved to play in the woods."

Merz said the boys, who were homeschooled and "very bright" were at his house a few days before Christmas.

"They came to my door to give me some cookies," Merz said. "They were wonderful kids, very thoughtful and polite. It's just a tragedy."

Hartrum said the hiking accident was a "freak situation."

Volner agreed. The sheriff said he constantly warns hikers about getting caught in the woods after dark.

"It was dark and rainy with no moonlight," Volner said. "I try to tell people all the time that we're far away from the ambient light of the city. There are no street lights or lights from houses out there. They were in the middle of a forest and it gets very, very dark."

Volner said the hikers were dressed for mild weather and they were soaking wet when they were found. He said hikers get lost all the time in the woods of Reynolds County.

"But this is the first time that it's turned tragic," Volner said.

According to Volner, the father and sons set out for a hike at 10:30 a.m. Saturday on the Ozark Trail. Heavy rain started about noon and turned to sleet and snow in the late afternoon.

Deputies and about 50 volunteers searched for the man and his sons on horseback and all terrain vehicles into the evening Saturday. By the time the father and his sons were found Sunday morning, temperatures had dropped into the 20s.

Hartrum said his son-in-law was a 10-year U.S. Air Force veteran who enjoyed exploring with his family.

While in the Air Force, Decareaux, who was originally from New Orleans, La., worked in the communications career field as an information technology specialist. He then served the Department of Defense in various civilian and contractor positions, the most recent with the U.S. Africa Command in Stuttgart, Germany. He joined the Defense Information Systems Agency Continental United States (DISA CONUS) as a civilian employee in July 2012.

"Dave was a very important member of our team, and we are deeply saddened by the sudden and tragic loss of him and his sons. Our hearts go out to his wife and surviving children, and we will be by the Decareaux family's side as we mourn the loss," said Army Col. John McLaughlin, commander of the DISA CONUSat Scott AFB.

The Decareaux family had moved in recent months back to the metro-east. Sarah Decareaux's parents are from Waterloo.

Decareaux was a pack leader in the Cub Scouts and his sons were both active in the organization and members of Pack 323 of Waterloo. On Monday the organization sent members a note saying they would be terribly missed.

"This heartbreaking story will certainly affect many in our program" said Alicia Lifrak, scout executive and CEO of the Lewis and Clark Council of the Boy Scouts of America. "We offer our heartfelt condolences to the Decareaux family and all the Scouts and Scouters in Pack 323 for the tragic loss this past weekend."

Funeral arrangements are pending for David, Dominic and Grant Decareaux. Quernheim Funeral Home in Waterloo is handling the arrangements.