Yahoo TV

Unprecedented rain in the northeast led to scenes like these: In New York and Philadelphia, streets turned into rivers with drivers stuck on flooded roads after remnants of Hurricane Ida brought torrential rain to New York, New Jersey and Philadelphia.

At least nine people were reportedly killed by flooding overnight.

The rain came on fast, Wednesday, crippling New York’s subway system and leaving residents stranded with stations flooded.

The governors of New York and New Jersey declared a state of emergency.

The National Weather Service - which issued a flash flood emergency in New York City for the first time ever - said the storm dumped 2 to 3 inches of rain per hour along the Philadelphia to New York City corridor.

Mayor Bill de Blasio described the rain and flooding on Wednesday night as a "historic weather event.”

"We saw a horrifying storm last night."

And on Thursday morning - recovery efforts were underway to bring back the transportation system.

New York Governor Kathy Hochul urged commuters to stay home from work and pleaded for patience.

Aerial footage, Thursday, showed parts of Philadelphia still under water.

In Montgomery County, outside of Philadelphia, some residents were rescued by emergency responders, and on Thursday morning video showed cars still submerged in water that has not receded.

More than 200,000 customers in the northeast were without power early on Thursday, mostly in Pennsylvania and New Jersey.