Six Vanish in Nevada Snow

Rescuers in Nevada are searching for two adults and four children who set out Sunday to play in mountain snow and haven't been seen since, CNN's Pamela Brown reports.

Frigid weather gripping much of the United States led to a frenzied search in northwest Nevada, where rescue teams are searching a mountainous area for two adults and four children who went to play in the snow and never returned.

James Glanton, 34, and Christina MacIntee, 25, are missing, along with Glanton's two children and MacIntee's niece and nephew. The children are 3 to 10 years old, the Pershing County Sheriff's Office said.

The group set out Sunday for Seven Troughs mountain range and haven't been seen since.

Fears intensified as the temperature plummeted to below zero.

Amanda Fitzpatrick, mother of 10-year-old Shelby Fitzpatrick, has joined the search in the freezing cold.

"It's been extremely hard, probably the hardest 24 to 36 hours of my life," she told CNN's Piers Morgan. "It's my baby girl."