Severe flash flooding hit the tri-state area on Monday, leading to subway disruptions and road closures in New York City, while prompting New Jersey to declare a state of emergency.

All five boroughs and Nassau County are under a flash flood warning through midnight.

“Flooding can be fatal and often occurs with little to no warning. Streets, basements, and below-ground areas can quickly become inundated. If you reside in a basement apartment or low-lying area, be prepared to relocate to higher ground,” warned NYC Emergency Management on X.

“Keep your Go Bag near the door and clear exit paths. Avoid flooded areas. Never walk or drive into water. Turn around, don’t drown.”

Westchester County was also under the same alert until 12:15 a.m., due to significant flooding on the southbound lanes of the Taconic State and Saw Mill River Parkway.

The 1, 2 and 3 trains are all suspended in Manhattan while the MTA addresses flooding across several stations, the agency said.

Inside the 23rd Street station, water appeared to be bursting out of a grate in the floor as it flooded the the area near the turnstiles, according to a video shared on X. Water also spilled under the doors and onto the subway itself as riders took refuge on the seats.

“Oh man, I might need a diaper!” one straphanger joked.

The Forest Hills-bound M and R trains are also operating under severe delays as multiple stations reportedly flooded in Queens.

The Franklin D. Roosevelt East River Drive in Manhattan had inches of water reaching up to cars’ tires shortly after 7 p.m., according to the NYC Department of Transportation cameras.

Drivers on the FDR had to carefully maneuver through the water as they inched down the road at just 2 miles per hour, according to a video shared by a driver caught in the flood on X.

People were actively driving against the current until they reached a point where the road was visible again.

For anyone needing to get into or out of the city, their options are limited after the Bronx River Parkway and Interstate 287 flooded to the point where drivers couldn’t even see the road, forcing many main routes to close, according to pictures shared on X.

In New Jersey, Gov. Phil Murphy declared a state of emergency and advised everyone to “stay indoors and avoid unnecessary travel,” he wrote on X.

Throughout the northern parts of the Garden State, cars and even emergency vehicles in towns like Somerville and Plainsville were overwhelmed and even partially overturned.

A flood warning was also extended in Fairfield County until 12:15 a.m., according to NBC Connecticut.

Last August, Connecticut was slammed by the worst flood it’d seen in two centuries, destroying entire roadways and sparking mudslides.