WILMINGTON, North Carolina - (Reuters) - Hurricane Irene lashed North Carolina with heavy winds, rain and surf Saturday as it neared land on a path threatening the densely populated US east coast with flooding and power outages.New York City ordered unprecedented evacuations and transit shutdowns as states from the Carolinas to Maine declared emergencies due to Irene, whose nearly 600 mile width guaranteed a stormy weekend for tens of millions of people.With winds of 90 miles per hour, Irene weakened slightly to a Category 1 hurricane on the five-step Saffir-Simpson scale by early Saturday but forecasters warned that it remained a large and dangerous storm.In the port and holiday city of Wilmington, North Carolina, thousands of people were without electricity as Irene's winds intensified. The streets were empty before dawn and the air was filled with the smell and sound of pine trees cracking under the advancing storm.At 5 a.m. EDT, the centre of Irene was about 35 miles south of Cape Lookout, North Carolina, the US National Hurricane Center said."Some weakening is expected after Irene reaches the coast of North Carolina but Irene is forecast to remain a hurricane as it moves near or over the mid-Atlantic states and New England," it said.In summer weather, hundreds of thousands of residents and vacationers had evacuated from Irene's path. Supermarkets and hardware stores were inundated with people stocking up on food, water, flashlights, batteries, generators and other supplies."Our number of customers has tripled in the last day or two as people actually said 'Wow, this thing is going to happen'," said Jack Gurnon, owner of a hardware store in Boston.Airlines canceled nearly 7,000 flights over the weekend and all three New York area airports were due to close to incoming flights at noon Saturday.President Barack Obama said the storm could be "extremely dangerous and costly" for a nation that recalls the destruction in 2005 from Hurricane Katrina, which swamped New Orleans, killed up to 1,800 people and caused $80 billion in damage.