(NBC NEWS) A couple and four children who vanished in sub-zero conditions in the mountains of northern Nevada were found safe Tuesday and revealed they had heated rocks in a fire to keep warm, officials said.

The six were found “in fairly good shape” after crews spent two nights searching for them, Pershing County police dispatcher Leslie Steward said.

“It’s a miracle. It really is,” Pershing County Sheriff Richard Machado told reporters.

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