CNN
—

Water rescue were out and about on Sunday after heavy rainfall caused a Flash flood emergency in Connecticut’s New Haven and Fairfield counties, according to the National Weather Service.

“Widespread flooding and water rescue operations” were underway on Sunday, the weather service warned. The emergency warning, which has since been downgraded to a flood warning, affected the towns of Waterbury, Danbury and the city of Fairfield.

David Stark of the National Weather Service in New York told CNN Weather that southwestern Connecticut received 6 to 10 inches of rain in a six to nine hour period Sunday, with most of it falling in the afternoon. Monroe, Connecticut, saw 10 inches of rain, a once-in-200-year event in the city.

In an update on Sunday evening, the weather service said that the towns of Oxford, Seymore and Cheshire, which are not affected by the flash flood emergency, were also affected by flooding.

“Between 5 and 15 centimeters of rain have fallen. Further rainfall of 1.3 to 2.5 centimeters is possible in the warning region. Flash floods are already occurring,” warned the weather service.

“The Department of Emergency Management continues to report water rescues, several landslides, numerous washed away roads and bridges, and flooding from downtown Fairfield County to northern New Haven County. In addition, emergency management officials are checking the integrity of several dams in the area,” the weather service said.

There are numerous other flash flood warnings in the northeast.

Nearly 1 million people in Suffolk County, New York, were affected by a flash flood emergency as of 4:30 a.m. Monday, the National Weather Service in New York City said.

The heavy rains have made road conditions dangerous, forcing several Connecticut cities and towns, including Stamford, Danbury, Southbury and Naugatuck, to close their roads.

“Several streets in the city are flooded due to heavy rainfall. We advise residents to stay in their homes if possible,” Southbury police said. “Emergency crews are deployed throughout the city responding to emergencies and road closures.”

On Sunday afternoon, heavy rains also triggered a landslide that caused a gas leak near an apartment complex in Danbury, which had to be evacuated, Danbury spokeswoman Erin Henry told CNN.

Another Danbury apartment complex on Main Street also had to be evacuated due to flooding, Henry added.

In a post on X, the Connecticut Department of Emergency Management and Homeland Security said the state’s operations center was monitoring the situation and had dispatched a search and rescue team to Southbury.

According to posts on the Connecticut State Parks X account, at least two state parks have been closed due to flooding.

Meanwhile, more than 700 flights were canceled at the three major airports near New York City on Sunday as thunderstorms swept across the region on Sunday evening.

According to FAA.gov, ground stops were in place at JFK, Newark and LaGuardia airports due to weather conditions. The stops were still in effect as of 10 p.m. ET.

Trains were also affected: Amtrak said that “inclement weather” flooded the tracks between Philadelphia’s 30th Street Station and New York’s Penn Station on Sunday.

“Crews have informed us that water on the tracks is gradually receding. Customers traveling to the affected area should expect delays of 60 to 90 minutes,” Amtrak said in a statement on its website.

CNN meteorologist Elisa Raffa and CNN’s Amanda Jackson and Susannah Cullinane contributed to this report.