More than 800,000 customers in 14 states lost electricity as an intense line of thunderstorms swept moved across the eastern U.S. on Halloween knocking down trees and power lines.

As of 8 a.m. ET, more than 600,000 still remained without power in New York, Pennsylvania, Maine, Connecticut and Virginia, according to poweroutage.us, which monitors U.S. utilities systems. 

The damaging winds were spawned by a cold front colliding with unusually warm and humid air in the east, including temperatures in the 70s in New York City and Washington, D.C., according to AccuWeather.com.

The 14 states were clustered in the Great Lakes, Northeast and mid-Atlantic areas that felt the brunt of the storm as it rolled east late Thursday and early Friday.

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One woman was critically injured near Colesville, Maryland, after a tree fell onto a vehicle late Thursday, WTOP reported.

As many as eight homes were destroyed by a possible tornado on one block in Thornburg Township, east of Philadelphia, WPVI reported. First responders had to cut through trees to reach people, including children and the elderly, trapped in their homes.

The National Weather Service noted hundreds of reports of downed trees from high winds as far south as Georgia and Tennessee, North Carolina and into New England.

In Pennsylvania, SEPTA suspended rail service early Friday on at least two lines because of downed trees and power lines across the area, WPVI reported. 

In Buffalo, 20 streets were blocked by downed trees, according to police.

Several school districts canceled classes in western New York, where power was expected to be out for two days in some areas.

In Milton, Massachusetts, south of Boston, wind gusts reached 68 mph at the Blue Hill Observatory Thursday night.

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