A frigid winter storm killed at least 18 people as it swept across the U.S.,

A frigid winter storm killed at least 18 people as it swept across the U.S.,

Blizzards knocking out power to hundreds of thousands of homes and businesses

Blizzards knocking out power to hundreds of thousands of homes and businesses

Storms are leaving millions of people on edge about the possibility of Christmas Eve blackouts.

Storms are leaving millions of people on edge about the possibility of Christmas Eve blackouts.

Across the US, officials have attributed deaths to exposure, car crashes, a falling tree limb and other effects of the storm.

Storm was nearly unprecedented in its scope,

Storm was nearly unprecedented in its scope,

Stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico.

Stretching from the Great Lakes near Canada to the Rio Grande along the border with Mexico.