A blizzard packing strong winds and heavy snowfall has pounded the US capital and surrounding areas, paralysing the region.
At least two people have been reported dead.
The National Weather Service put the Washington-Baltimore metropolitan area under a rare 24-hour blizzard warning until late tonight.
The storm, dubbed 'Snowpocalypse' and 'Snowmageddon' by many locals, stretched from Indiana to Pennsylvania and into parts of New York and North Carolina, creating treacherous travel conditions, shutting Washington area airports and leading several states to declare emergencies.
The inclement weather was deemed responsible for at least two fatalities - a father and son who were hit by a truck on a road in Virginia when they stopped to help a stranded motorist, local media reported.
Forecasters said the Washington region would be hardest-hit, describing travel conditions in the area as 'hazardous and life-threatening'.
All flights were canceled for Saturday at Reagan National Airport, and most planes were grounded at Dulles International and Baltimore-Washington International Airports, although all three area airports formally remained open.
The National Weather Service forecast up to 76cm (30'') of snow in the capital region, which would shatter Washington's 88-year-old record snowfall of 28'', in the 'Great Knickerbocker Storm'.
That blizzard, which slammed the region in January 1922, got its name from the collapse of the Knickerbocker Theatre in Washington which killed nearly 100 people.
Late Friday, the national capital was left without bus service as the metropolitan transit authority deemed the roadways 'impassable'.
The metro shut down 40 above-ground stations.
The governors of Virginia, Maryland and Delaware declared states of emergency, a move that puts the National Guard on alert.
Nearly 28,000 power outages were reported in the area, electricity companies said.
Last-minute shoppers besieged supermarkets Friday to stock up on provisions, as official warnings blared on radio and television, urging residents to be prepared to stay inside for up to five days.
Courts, schools, government offices, and even military bases closed early on Friday to beat the storm, which started to dump snow on the capital and its suburbs by mid-day.
