ST. LOUIS – Whether it was the bone-chilling rain or the pitch-black darkness while lost in a forest, circumstances that doomed an Air Force veteran and two young sons on a Missouri hike illustrate the need for simple precautions that could avert similar tragedies, officials say.

Authorities said Tuesday experienced hiker David Decareaux and two of his boys, ages 10 and 8, weren’t equipped for the elements when they set out Saturday on the Mark Twain National Forest’s Ozark Trail in light clothing, only to succumb to temperatures that plunged to freezing and a downpour that made that worse.

Their bodies were found the next day on the trail, their surviving dog beside them.

Such deaths are rare, marking the first among hikers in the 1.5 million-acre forest in at least two decades.

Experts say other hikers should take note: Don’t take any foray into a forest for granted, particularly during the winter when daylight is shorter and weather can be unforgiving.

“It’s not Disneyland,” said Charlotte Wiggins, a spokeswoman for the forest.

Forecasters had warned for days that the weather would turn ugly Saturday, but it’s not clear whether Decareaux, 36, knew that when he ventured out with sons Dominic and Grant. They had no compass or supplies for cold weather.

With the temperature unseasonably near 60, Decareaux was wearing only a light jacket. One of his sons was clad in a fleece pullover, the other a sweater.

Hours into the hike, Reynolds County Sheriff Tom Volner said, a couple who drove by the Decareauxes offered them the five-mile ride back to the lodge, where Decareaux’s wife and their three other children awaited. Decareaux declined and pressed on.

But the weather worsened. The temperature by evening sank into the 40s, and a storm drenched the area with 2 inches of rain.

Somehow, the hikers made a crucial mistake. Instead of veering onto the Blue Trail to get back to the lodge, they continued on the Ozark trail, Volner said.