Hurricane Isabel is unleashing powerful winds and heavy rains on vast stretches of the U.S. East Coast. Isabel's fierce 160 kilometer-an-hour maximum winds are expected to diminish as the storm travels northward over land.

Hurricane Isabel has downed trees and power lines, leaving hundreds of thousands of homes and businesses without electricity in North Carolina and Virginia. Isabel has sparked storm surges that ripped up seaside piers. The hurricane has also damaged roofs and storefronts, and sent debris hurtling through the air.

Bob Morris, the police chief in the North Carolina seaside resort town of Kitty Hawk "A lot of trees on power lines. A few houses have been hit by trees. We are starting to get some pretty good flooding on our ocean side - a lot of wind and rain."

Classified as a moderate category 2 hurricane on a 1-5 scale when it came ashore, Isabel is expected to dump as much as 30 centimeters of rain on communities in its path. Already, some areas of North Carolina and Virginia are reporting flooding, and more than 300,000 residents of the two states are being urged to seek higher ground.

Kitty Hawk Police Chief Bob Morris says he is thankful that Isabel's winds subsided in the days before the storm reached land, and that local residents heeded an evacuation order.

"It was probably one of the most orderly evacuations I can ever remember. Folks got out early, and, based on that, we did not have a last-minute rush with traffic jams."

Isabel is moving on a north-northwest track that is expected to take the storm over Maryland and Pennsylvania. In Washington, schools and government offices closed Thursday in anticipation of Isabel's expected arrival.