Tropical Storm Ida dropped historic rainfall on the tri-state area on Wednesday, causing mass flooding on roadways, forcing the MTA to shut down nearly every subway line, and leaving tens of thousands without power.

NYC announced a travel ban due to "severe weather," starting at 12:50 a.m. and lasting until 5 a.m. on Thursday morning: "All non-emergency vehicles must be off NYC streets and highways."

For the first time ever, the National Weather Service issued a Flash Flood Emergency for New York City. In Central Park, 3.15 inches of rain was recorded in one hour, from 8:51 p.m. to 9:51 p.m., breaking an 11-day-old record of 1.94 inches.

At around 11 p.m., Mayor Bill de Blasio declared a state of emergency.

"It’s very very troubling and it came on so suddenly," he said on WABC 7. "We’ve got a serious situation for a couple of hours. It’s absolutely crucial for people to get off the roads." He also noted the subway lines "are having tremendous problems." Soon after, he announced on WCBS 2: “We’re declaring a state of emergency for NYC, I just made that decision."

"We’re seeing a rainfall we almost never see," he said. "The subways are basically out of commission at this point."

By 11 p.m., every subway line was suspended. The system is seeing significant flooding:

Justin King, a 40-year-old musician, was on a D train from Port Authority when the subway stopped abruptly at 23rd Street. “We sat on the train for 20 minutes with no announcement,” he said. “Eventually they said trains weren’t running because the tracks were flooded. All the water from up there is going down there.” King said he was planning to sleep in Brooklyn, but wasn’t sure how he’d make it across the East River.

The MTA has crews pumping water out of stations to move subway cars that are stuck between stations. By about 12:30 a.m., at least six trains that were stuck between stations had been evacuated.

New York Governor Kathy Hochul said just before midnight on CNN, "Right now we are in a very dire situation." Soon after during an appearance on NY1 she officially declared a state of emergency.

New Jersey Transit, Long Island Rail Road, and Metro-North have suspended service, and asked customers to check in the morning about service.

The NYC Transit subway Twitter account replied to a customer at 12:40 a.m., "We won't operate trains tomorrow if it's hazardous. We don't know yet what service will look like in the morning, but please do stay tuned for updates."

Acting MTA Chair Janno Lieber called the situation "historic and challenging" in a statement, and said that the agency was focused on evacuating everyone who were stuck in trains "after up to six inches of rain fell within hours." He urged New Yorkers to avoid traveling at this time while they are "deploying maximum pump capacity and surging workers into the system when it's safe so that as this epic storm abates, service can be restored as soon as possible."

People navigate heavy rains and flooded walkways at the Billie Jean King National Tennis Center in Queens as the remnants of Hurricane Ida hit the area.

Parts of the Bronx were also under a tornado warning as of 9 p.m.

Roadways have also flooded. Mayor de Blasio said on Wednesday night that FDNY, EMS and NYPD had been working to get getting people out of their cars.

New Jersey Governor Murphy declared a state of emergency on Wednesday night. Multiple tornadoes were seen across NJ, and the National Weather Service confirmed a tornado in Woodbury Heights.

Parts of Trenton were evacuated, due to concerns about flooding from the Delaware River. The mayor of Passaic said that at least one person died after being trapped in a car.

Newark Airport closed due to flooding around 11 p.m., but reopened just before midnight with limited service.

Murphy said at least 81,000 power outages were reported in NJ, while de Blasio said 5,300 customers were without power in NYC. Thousands of customers across Westchester County and Long Island are also reporting outages, according to Con Edison and PSEG.