A massive storm, billed as the worst, in decades has barrelled northeast thorough US states, leaving vast swaths from Chicago to New York paralysed by snow and ice.
Hundreds of motorists were stranded overnight on Wednesday, and airports and schools were forced to close.
More than 5,300 flights were cancelled nationwide on Wednesday, according to flight tracking service FlightAware. That came a day after airlines grounded 12,630 flights due to the storm.
Chicago had almost 50cm of snow, ranking the storm the third-largest on record to hit the city, closing O'Hare International Airport - a major US hub.
The city closed public schools for the first time in 12 years and shut down Lake Shore Drive, where hundreds of motorists were stranded for 12 hours after multiple car accidents.
As much as 46 centimetres of snow fell in Missouri, more than 30 centimetres dropped on northern Indiana and southeast Kansas, and Oklahoma saw up to a foot.
Forecasters warned ice accumulations could knock down some tree limbs and power lines across the storm's more than 3,220-kilometre path.
The storm's powerful punch came from cold air that swept down from Canada, clashing with warm, moist air coming up from the south, the National Weather Service said.