At least five people died as Tropical Storm Isaias made its way up the US Atlantic Coast, including two deaths at a North Carolina mobile home park that was struck by a tornado spun off by hurricane-force winds.
The storm knocked out power to more than 2.8 million homes and businesses from New York to North Carolina.
Isaias, which was briefly a Category 1 hurricane when it made landfall in North Carolina late on Monday, reduced the mobile home park in the north of the state to rubble hours later, leaving two people dead.
"It doesn't look real. It looks like something on TV. There's nothing there," Bertie County Sheriff John Holley told local reporters. "Vehicles are turned over. Vehicles are piled on top of each other. It's just very sad."
A mother and her two children who were missing for hours after the storm ripped through the area were later found safe.
In Mechanicsville, North Carolina, a large tree fell on a car, killing the driver, the St Mary's County Sheriff's Office said.
Elsewhere, strong winds from the storm knocked down trees and power lines across Massachusetts, leaving more than 220,000 customers without power, CBS Boston reported.
A man in the New York City borough of Queens became the fourth fatality when a tree crushed a car he was inside, local authorities said.
Social media images showed tornadoes in Cape May, Marmora and Long Beach Island along New Jersey's southern shore, and tornado damage in Dover, Delaware.
New York City, much of New Jersey, all of Massachusetts and other parts of New England went under a tornado watch. New York state officials temporarily shut down coronavirus testing centres as a precaution.
The fast-moving storm is tracking northeast according to the National Hurricane Center and is expected to sweep through the northeastern United States and into southern Canada overnight.
Washington, Baltimore and other cities on or near the Atlantic coast experienced heavy rainfall.