NEW YORK CITY, Sep 1 (Aljazeera) - New York Governor Kathy Hochul has declared a state of emergency as the remnants of storm Ida caused enormous flooding in New York City and across the northeastern United States.

“I am declaring a state of emergency to help New Yorkers affected by tonight’s storm,” Hochul tweeted on Thursday, after Ida, which slammed into the southern United States as a Category 4 hurricane on Sunday, caused tornadoes and flooding as it steamed north.

Nearly all New York City subway lines were suspended late on Wednesday as at least five flash-flood emergencies were issued by the National Weather Service, stretching from just west of Philadelphia through northern New Jersey.

Earlier in the night, New Jersey Governor Phil Murphy also declared a state of emergency in response to Ida.

Storm damage from Ida astounded officials on Wednesday three days after the powerful hurricane pounded southern Louisiana, as reconnaissance flights revealed entire communities devastated by winds and floods.