Recently there was an article in Scientific American (in the last 6 months) which covered the same ground. It had some really great illustrations of all the tunnels under Manhatten. -dave
From: "Perry E. Metzger" <perry@piermont.com>
Steam, rats, tunnel fires, steam system explosions, and water main breaks take out lots of fiber in NYC -- probably more that backhoe fade takes out elsewhere. However, backhoe fade itself (though not unheard of) is much rarer, largely because the conduits are deep and the streets are so jam packed that if you make a mistake about where you are it will be obvious Very Very Quickly.
Smithsonian Magazine had a fascinating article a few years back about the infrastructure jockeys who plan and install new stuff under the streets of Manhattan. "Jam-packed" might qualify for the understatement of the year award -- there is a lot of stuff down there, including lots (most?) which is incorrectly documented or not documented at all. Worth taking the time to look up if you're the kind of person who geeks out over that sort of thing.
---Rob