Tropical storm Isaias left four people dead as it pounded the US eastern seaboard with driving winds and heavy rain, leaving millions of households without power Wednesday.

Locals try to rescue their belonging after the overflow of the Magua river caused by heavy rains caused during Isaias storm in the city of Hato Mayor, northwest of Santo Domingo, Dominican Republic, on July 31, 2020 Locals try to rescue their belonging after the overflow of the Magua river caused by heavy rains caused during Isaias storm in the city of Hato Mayor, northwest of Santo Domingo, Dominican Republic, on July 31, 2020 Photo: afp / Erika SANTELICES

A tornado ripped through a mobile home park in North Carolina killing two people said state governor Roy Cooper on Tuesday, while two more died as trees fell on their cars -- one in New York and one in Maryland.

The tropical storm was downgraded late Tuesday as it streaked into southeastern Canada, where forecasters warned of heavy rain to come.

Forecast path of tropical storm Isaias Forecast path of tropical storm Isaias Photo: AFP / Nicolas RAMALLO

Earlier, wind gusts up to 50 mph (80 kph) wreaked havoc across eastern states of the US, littering streets with debris and forcing the cancellation of scores of flights.

Video footage from New Jersey showed a roof being torn off a house as residents were told to stay indoors because of a threat of tornadoes.

Hurricane Isaias unleashes flooding, topples trees and knocks out power for thousands of people in Puerto Rico. Hurricane Isaias unleashes flooding, topples trees and knocks out power for thousands of people in Puerto Rico. Photo: CRISTINA ARRIETA / ESN

About three million houses were without power by early Wednesday morning across several states, utilities companies reported -- with New Jersey and New York worst hit by the outages.

Isaias quickly moved up the East Coast after slamming into the coast of North Carolina overnight with hurricane strength.

A man walks under pouring rain during Isaias storm in Santo Domingo, on July 30, 2020 A man walks under pouring rain during Isaias storm in Santo Domingo, on July 30, 2020 Photo: afp / Erika SANTELICES

"Isaias hit North Carolina head-on," Governor Cooper, adding that roads were being cleared and electricity restored.

"As clean-up continues, don't forget the pandemic is still with us. So help your neighbor, but do it safely by wearing your mask, keeping your distance and bringing your hand sanitizer."

Workers set up temporary plastic flood barriers and sandbags known as 'Tiger Dams' in lower Manhattan to protect the area from flooding as tropical storm Isaias approaches New York City on August 3, 2020 Workers set up temporary plastic flood barriers and sandbags known as 'Tiger Dams' in lower Manhattan to protect the area from flooding as tropical storm Isaias approaches New York City on August 3, 2020 Photo: AFP / Angela Weiss

New York authorities, ever-wary of the devastating damage caused by Superstorm Sandy in 2012, set up temporary flood barriers in Lower Manhattan in case of storm surge.

The orange flexible tubes known as "Tiger Dams" were put up in low-lying areas.

Rough seas and winds develop near North Myrtle Beach in South Carolina as Hurricane Isaias approaches US eastern seaboard. The storm is expected to bring life-threatening storm surges to North and South Carolina. Rough seas and winds develop near North Myrtle Beach in South Carolina as Hurricane Isaias approaches US eastern seaboard. The storm is expected to bring life-threatening storm surges to North and South Carolina. Photo: AFPTV / Logan CYRUS

Public transport services were also briefly suspended including New York's famous Staten Island ferry.

But the rain turned out not to be as heavy as feared.

"The storm has been much more of a wind event than flooding so far, thank God," New York mayor Bill de Blasio told local news station NY1.

At least 78 flights were canceled at New York's LaGuardia Airport. There were 55 cancelations at JFK.

The fast-moving storm is tracking northeast according to the NHC 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.

"I urge everyone in the storm's path to remain alert and to follow the guidance of your state and local authorities," President Donald Trump said Tuesday during a White House press conference.

The storm earlier dumped torrential rain on the Bahamas, felling trees and flooding streets, before emergency management officials on Sunday gave the all-clear.

At least one person died in Puerto Rico and the storm also lashed Haiti and the Dominican Republic.