Pedestrians look at a tree blown down by high winds that blocked part of Woodley Road NW in Washington D.C., the United States, on March 2, 2018. (Xinhua/Li Muzi)

WASHINGTON, March 3 (Xinhua) -- At least seven people have died by Saturday morning from the Nor'easter windstorm which is retreating after wreaking havoc across the U.S. East Coast, causing heavy flooding, massive power shortage and thousands of flight cancellations in and out of the country.

There were still 2.3 million customers without power in 12 states across the northeastern America on early Saturday, said an ABC News report.

A worker cuts off branches of a tree blown down by high winds that blocked part of Woodley Road NW in Washington D.C., the United States, on March 2, 2018. (Xinhua/Li Muzi)

All the victims, including two children, were killed by falling trees.

A six-year-old boy died in the state of Virginia after a tree fell on his family's home early Friday morning when he was sleeping. And in New York state, an 11-year-old boy died when a tree fell onto his home and trapped him underneath.

Others included a 77-year-old woman in Baltimore, a man in his 70s in Rhode Island, a 57-year-old man in Pennsylvania and a 44-year-old man in Virginia.

A tree blown down by high winds blocks part of Woodley Road NW in Washington D.C., the United States, on March 2, 2018. (Xinhua/Li Muzi)

On Saturday morning, numerous roads across the region were still closed due to debris, fallen trees and power lines. Rail service across the Northeast was also impacted significantly with Amtrak suspending all service on the Northeast Corridor line.

Meanwhile, widespread street flooding was reported in eastern Massachusetts with storm surge reported to be as high as three feet.

Leaves are blown into the air by high winds above Lincoln Memorial Reflecting Pool in Washington, the United States, on March 2, 2018. (Xinhua/Li Muzi)

The Boston Harbor rose to 14.67 feet on Friday, marking the third-highest on record in a century. Another high tide near 14.6 feet is forecast around noon on Saturday.

On Sunday, the storm is gone and winds will be even calmer, according to the U.S. National Weather Service.