Tropical Storm Isaias killed at least one person and knocked out power to hundreds of thousands as it pummeled North Carolina and Virginia on a path toward Washington and other cities of the U.S. Northeast on Tuesday.

The fast-moving storm unleashed heavy rain and strong winds across southeastern Virginia, with the center of the storm about 100 miles (160 km) south of Washington as of 8 a.m. Eastern time (1200 GMT), moving toward the north at 33 miles per hour (54 kph), the National Hurricane Center said.

A tropical storm warning remained in effect all the way to Maine, with major cities such as Washington, Philadelphia and New York in the potential path.

The Washington area was experiencing heavy rains as Isaias blew through on Tuesday morning, with authorities warning of flash floods, and some low-lying roads closed due to flooding.

More than 600,000 homes and businesses in North Carolina and Virginia were without power, according to electric companies. 

The storm had regained hurricane strength late on Monday just before making landfall in southern North Carolina shortly before midnight as a Category 1 hurricane, the least intense on the five-level Saffir-Simpson scale.

It was downgraded to a tropical storm while flooding homes and streets in North Carolina, killing one person and injuring several others in a mobile home park, Governor Roy Cooper told ABC's "Good Morning America."

Isaias blew maximum sustained winds of 70 mph (110 kph) while threatening to spread tornadoes through midday from southeast Virginia to New Jersey, the hurricane center said.

At least one tornado was reported in North Carolina, Cooper said.

"All in all, this storm got in and got out pretty quickly and that's a good sign for potential river flooding, which we hope will not be serious," Cooper said.

(Reporting by Daniel Trotta; Editing by Bernadette Baum) ((; +1 646 223 4186))