THE city of New York has declared a state of emergency due to “brutal flooding” after being caught by the tail end of Hurricane Ida.

The National Weather Service (NSW) has also issued its first ever flash flood warning in the city as streets, subway stations and airports were flooded.

At least one person has been killed in New Jersey during the extreme weather, according to the Washington Post.

New York was placed on tornado watch on Wednesday night after the area was hit by the remnants of tropical storm Ida.

Announcing the state of emergency at around 4.30am UK time, mayor Bill de Blasio wrote: “We’re enduring an historic weather event tonight with record breaking rain across the city, brutal flooding and dangerous conditions on our roads.

“Please stay off the streets tonight and let our first responders and emergency services get their work done.

“If you’re thinking of going outside, don’t. Stay off the subways. Stay off the roads. Don’t drive into these heavy waters. Stay inside.”

He added: “We’re keeping our eyes on our power grid. We’ve seen about 5,300 customers without power.

“We expect the rain to stop in the next few hours. But until then, again, if you’re not inside, get inside.”

New Jersey and Pennsylvania have also been hit by torrential rain and strong winds, with at least one tornado collapsing the roof of a US Postal Service building and threatening to overrun a dam on the way.

Governor Phil Murphy declared a state of emergency in all of New Jersey’s 21 counties, urging people to stay off the flooded roads.

The NWS confirmed that a tornado had struck and issued a flood warning to New York residents.

The service wrote on Twitter that “this particular warning for NYC is the second time we’ve ever issued a Flash Flood Emergency (It’s the first one for NYC)"

It added: "The first time we’ve issued a Flash Flood Emergency was for Northeast New Jersey an hour ago”.

The weather also forced a suspension in play at the US Open when a night match had to be halted – despite it being played under a roof.

Play between Kevin Anderson and Diego Schwartzman inside the Louis Armstrong Stadium was stopped after the torrential rain began blowing in sideways through openings under the roof.

The freak conditions forced the players off the soaking wet court while spectators had to shelter under umbrellas.

The match was initially interrupted for 35 minutes while the surface was dried but after a brief restart – during which 11th seed Schwartzman won the first set on a tie-break – the match was once again suspended.