Sewer...

 

We’ve got a very serious situation for the coming hours,” de Blasio said. “Get off the streets, get to a safe place. … The next few hours are a very tenuous situation.”

De Blasio said he’s been in contact with Governor Kathy Hochul about the flooding conditions across the city. He stressed that the rainfall has been so intense, heavy and fast that it simply overwhelmed the city’s sewer.  

So to prepare for the next storm, the MTA didn't want to disturb the streets, most of the Second Avenue Subway stations were mined from underground, which is more expensive. The stations under Second Avenue are also extremely deep nearly 100 feet below ground, about twice as deep as the Purple Line.

Excellent preparation for the next storm. Just a thought.