It was double trouble for two brothers in northwestern Minnesota, who separately crashed through thin ice in their new vehicles last week.

Both survived to tell the tale.

Here's what happened: One brother was leaving the family's ice fishing house on Little Pine Lake near Perham on Friday night, heading for shore in his 2011 Ford F-150 truck. There was thick fog, and he got disoriented and drove into open water where the Ottertail River enters the lake.

"He swam out and walked home" a half mile, DNR conservation officer Chris Vinton said. He had only had the truck for a few months, Vinton said.

The next morning, his brother left the shore at least a mile away in his 2012 Jeep, heading for their ice fishing house. The vehicle hit thin ice and started sinking.

"He got out before it went down," Vinton said. "It still had temporary tags on it.

Vinton said there was no explanation for the thin ice. "It was just a fluke thin spot," he said. Ice nearby was 20 inches thick. Both vehicles submerged in about 7 feet of water, he said.

Both men are in their 40s and know the lake well.

"It's so treacherous when driving on the ice -- it's never safe," Vinton said. "We've had horrible ice-making weather, and people need to be mindful of it. If you go onto the ice, always be prepared to fall in."

Vinton estimated that at least 40 fish houses in his area have gone through thin ice this season.

North Shore fishingSalmon and coho fishing has been hot on the North Shore of Lake Superior recently, with some anglers getting out on the lake in boats.