In article ,
Han wrote:

Smitty Two wrote in
news
In article ,
aemeijers wrote:

And as we approach the tenth anniversary of the towers being brought
down, and to bring in an AHR angle, ISTR that checking and
reinforcing the slurry wall perimeters of the WTC foundation
footprint was one of the first things they did post-attack, lest the
Hudson River fill the hole and the attached subway tunnels.

They still often find surprises when they dig holes in NYC. It is
almost starting to be an old city, and it is only in recent decades
that the 'as built' documentation is very complete.

It isn't just subways down there, either. IIRC from a documentary I
saw a few years ago, there are layers and layers and layers of
underground utilities, going down the equivalent of several stories. I
don't know how susceptible they are to flooding.

Yes, there are many layers (probably crossing over and over) of all kinds
of utilities. Most should be really waterproofsince they are in ground,
and surrounded by water, sewage, and steam lines.

My impression was that they were in service tunnels, not just buried.
But I could be mis-remembering the show I saw.