A polar vortex has put much of the Midwestern United States into a deep freeze this week, with temperatures rivaling the Arctic. Schools, businesses, roads and travel were brought to a standstill in many parts of the country, with residents warned to stay inside.
A winter storm has slammed the U.S. Northeast with heavy snow and powerful winds, causing power outages and damaging trees, particularly in Massachusetts.
Officials canceled hundreds of flights ahead of a nor'easter expected to drop more than a foot of snow and create blizzard conditions in parts of the Northeast.