A winter storm has caused travel chaos on the US north-east and is being blamed for up to 17 deaths.
Nearly 4,000 US flights were cancelled on Thursday as snow blanketed parts of the north-eastern US seaboard as well as eastern Canada.
Boston could get up to 18in (45cm) of snow while rough waters have already triggered coastal floods in the region.
The storm, known as a "bomb cyclone", is expected to continue to affect eastern North America into the weekend.
After the snowfall ends, temperatures are expected to plunge as frigid air lingering over the North Pole heads towards the US mid-Atlantic region.
Experts warn that parts of the US may record their lowest-ever temperatures on Friday and Saturday.
