Large parts of the US are bracing for a deep freeze that is forecast to plunge major cities into chaos.
North-eastern states of New York and New Jersey have already declared states of emergency as winter storm Stella swept in.
Some 50 million people along the Eastern Seaboard are under blizzard warnings with up to 60 cm of snow forecast by early Wednesday.
New York Mayor Bill de Blasio issued his own warning:
“Stay off the streets, for your own good, for your own safety, but also to help the sanitation department to keep the streets clear. If you must go out, do so for as limited a time period as possible.”
Schools have been closed and thousands of flights have been cancelled affecting travel plans including those of German Chancellor Angela Merkel. She had been due to meet President Donald Trump in Washington today but has postponed her trip until Friday.