A brutal cold spell that paralysed the US Midwest, eased yesterday with forecasts predicting a rapid thaw. 
Blocks of ice floated down the river that runs through downtown Chicago, the rushing waters of the Niagara Falls were frozen in some places, and half the Great Lakes were covered in ice. According to US media reports, at least 21 persons have died in the snow storm early in the week.
The two days of intense cold from the so-called polar vortex that descended on the US Midwest and Northeast will go down in memory for its scenes of winter at its most bitter.
