Major cold front hits the United States

US weather forecasters are monitoring an unusually large and intense winter storm that is expected to bring dangerously cold air to more than half of the country through the weekend and into early next week, with tens of millions of people under winter storm warnings stretching from New Mexico to New England, more than 8,000 flights cancelled, widespread power outages anticipated, and weather emergencies declared by at least 14 state governors. Yinka Oyetade reports.