US east coast on hurricane alert

Tropical storm-force winds from Hurricane Irene have begun lashing the US east coast with rain, with the potential to cause billions of dollars in damage
At least 65 million people could be affected along a densely populated arc that includes Washington, Baltimore, Philadelphia, New York and Boston.
A hurricane warning is in effect from North Carolina all the way to Massachusetts - including for New York City, where more than a quarter of a million people have been ordered to evacuate ahead of Irene's approach. It was the first hurricane warning issued for New York City in more than two decades.
Officials declared emergencies, called up hundreds of National Guard troops, shut down public transport systems and begged hundreds of thousands of people to obey evacuation orders. Airlines cancelled more than 2,000 weekend flights.
Speaking from Martha's Vineyard Island where he is on holiday, President Barack Obama said all indications point to the storm being a historic hurricane.
"Don't wait. Don't delay," said Mr Obama, who decided to cut short his summer holiday by a day and return to Washington. "I cannot stress this highly enough: If you are in the projected path of this hurricane, you have to take precautions now."
The latest forecasts showed Irene crashing into the North Carolina coastline, then churning up the Eastern Seaboard and drenching areas from Virginia to New York City before a weakened storm reaches New England.
Rain and tropical storm-force winds of at least 39 mph were already pelting North and South Carolina as Irene trudged north, snapping power lines and flooding streets.
Thousands were without power. In Charleston, South Carolina, several people had to be rescued after a tree fell on their car, trapping them.
In addition to widespread wind and water damage, Irene could also push crude oil prices higher if it disrupts refineries in Delaware, New Jersey, Pennsylvania and Virginia, which produce nearly 8% of US petrol and diesel fuel.