The deep freeze transformed Niagara Falls in northern New York state into an icy spectacle, encasing the trees around it into crystal shells and drawing tourists.
The Niagara River is flowing below the ice cover, so the falls aren't completely frozen.
But days of extreme cold have created a thick coating of ice and snow on every surface near the falls, including railings, trees and boulders.
Eighteen of the deaths this week occurred in Tennessee. A man, woman and their adult son died in a fire in Knox County. Firefighters said they had difficulty reaching them because the second level of the house collapsed on to the lower level. Other people in Tennessee died from hypothermia and in car accidents, and a dialysis patient is reported to have died after he was unable to get treatment because of weather.
More than 2700 people are without power as more severe cold, freezing rain and snow are predicted for the next few days, Tennessee officials said. Dangerously cold conditions continue to grip a large part of the Eastern United States, CNN meteorologists said, with more than 125 million Americans under a wind chill warning or advisory.
Wind chills will go as low as -40C in some places.
Snow, sleet, and freezing rain will spread over the mid-South and into the mid-Atlantic over the next couple of days.
Ice storm warnings are in effect for Nashville, where heavy ice could again cause widespread power outages.
Winter storm warnings again cover much of Kentucky.
