The remnants of Hurricane Ida have inundated large stretches of the north-eastern US killing at least 22 people in flooding from New York to Maryland as basements filled with water, rivers swelled to record levels and roads turned into canals.

Nine people died in New York City, police said, one of them in a car and eight in flooded basement apartments that often serve as relatively affordable homes for low-income people.

Officials said at least eight died in New Jersey and three in Pennsylvania’s suburban Montgomery County, where one was killed by a falling tree, one drowned in a car and another in a home.

The storm also spawned tornadoes, including one that ripped apart homes and toppled silos in Mullica Hill, New Jersey.

Water from record rainfall cascaded into New York City subway tunnels, trapping at least 17 trains and forcing the cancellation of services throughout the night and early morning.

Videos showed passengers standing on seats in carriages filled with water. All riders were evacuated safely, officials said.

The nation’s largest city is slowly recovering from catastrophic flooding that was reminiscent of Superstorm Sandy in 2012.

The National Weather Service recorded 3.15 inches of rain in Central Park in one hour on Wednesday night, far surpassing the previous recorded high of 1.94 inches that fell in an hour during Henri on August 21.

Major flooding along the Schuylkill River in Pennsylvania swamped highways, submerged cars and disrupted rail services in the Philadelphia area.

In a tweet, city officials predicted “historic flooding” on Thursday as river levels continued to rise, and the riverside community of Manayunk remained largely under water.

The rain in the tri-state area ended by daybreak on Thursday as rescuers searched for stranded people and braced for potentially finding more bodies.

“We’re enduring an historic weather event tonight with record breaking rain across the city, brutal flooding and dangerous conditions on our roads,” New York mayor Bill de Blasio said while declaring a state of emergency in New York City late in Wednesday.

Police in Connecticut were investigating a report of a person missing due to the flooding in Woodbury. In Passaic, New Jersey, a 70-year-old man was swept away after his family was rescued from their car.

Among the deaths reported in New York City, a 48-year-old woman and a 66-year-old man died after being found at separate residences, and a 43-year-old woman and a 22-year-old man died after being found inside a home.

Heavy wind and rain collapsed the roof of a US Postal Service building in New Jersey and threatened to overrun a dam in Pennsylvania.

The National Weather Service in New York issued its first-ever set of flash flood emergencies in the region on Wednesday night, alerts only sent in the most dangerous conditions.

An emergency was issued on August 22 in Waverly, Tennessee, when flooding in the town and surrounding county killed 20 people after the rainfall in one day shattered the state record.

That was the start of a deadly two weeks across the nation. Wildfires are threatening Lake Tahoe, Tropical Storm Henri struck the north east and Ida hit Louisiana as the fifth-strongest storm to strike the US mainland, leaving a million people without power.

Rescues took place all over New York City as its 8.8 million people saw much worse flooding than from Henri.

New Jersey governor Phil Murphy declared a state of emergency in all 21 counties, urging people to stay off flooded roads. Meteorologists warned that rivers are not likely to peak for a few more days, raising the possibility of more widespread flooding.

At least 220,000 customers were without power in the region, with most of the outages in New Jersey and Pennsylvania. More than 35,000 customers were without power on Thursday morning in New York City, Long Island and its northern suburbs.

The National Weather Service said it was investigating a possible tornado on Cape Cod at around 1am on Thursday. Meteorologist Bill Simpson said reported damage including downed trees.