Snow blankets America

At least nine deaths have been reported across the country connected with the polar air mass that swept over North America during the past few days.

Homeless shelters and public buildings took in people who were freezing outside.

In Oklahoma, a depleted supply of propane due to extreme weather led Governor Mary Fallin to declare a state of emergency, waiving licensing requirements for out-of-state transportation companies to allow them to bring in propane.

Oil refiners were also hit, with Marathon Petroleum Corp and Exxon Mobil Corp both experiencing cold-related outages.

PJM Interconnection, the agency that oversees the electric grid supplying the mid-Atlantic and parts of the Midwest, said electricity suppliers were struggling to keep up with surging demand as the cold forced some power plants to shut.

Authorities have put about half of the United States under a wind chill warning or cold weather advisory.

The cold snap could cost the U.S. economy up to $5 billion, when lost productivity and lost retail sales are accounted for, estimated Evan Gold, senior vice president at Planalytics, which tracks weather for businesses. He said about 200 million people in

Four cold and storm-related deaths were reported around Chicago and an elderly woman was found dead outside her Indianapolis home early Monday.