A couple takes a photo of ice, formed on the American Falls in Niagara Falls, New York, due to subzero temperatures, viewed from the Canadian side, in Niagara Falls, Ontario, Canada, January 22, 2019. Niagara Falls look stunning as temperatures plunge after a winter storm in the Midwest. REUTERS/Moe Doiron

Water flows around ice, formed on the American Falls in Niagara Falls, New York, due to subzero temperatures, viewed from the Canadian side, in Niagara Falls, Ontario, Canada, January 22, 2019. The storm brought snow as it moved from east to west it was strengthened by Arctic air from Canada. REUTERS/Moe Doiron

A man helps his son with his mittens during a visit to Niagara Falls, Ontario, Canada January 22, 2019. The weather service has issued warnings for a swath in eastern U.S. that is home to 100 million people. REUTERS/Moe Doiron

A couple takes a photo of ice formed on the American Falls in Niagara Falls, New York, due to subzero temperatures, viewed from the Canadian side, in Niagara Falls, Ontario, Canada, January 22, 2019. REUTERS/Moe Doiron

Visitors take a "selfie" as ice and snow coat a railing near the brink of the Horseshoe Falls, due to subzero temperatures in Niagara Falls, Ontario, Canada January 22, 2019. REUTERS/Moe Doiron

An aerial photo taken over the American side shows water flowing around ice due to subzero temperatures in Niagara Falls, New York, U.S. January 22, 2019. REUTERS/Dronebase