What Lies Beneath New York City?

July 20, 2007 — -- After Wednesday's steam-pipe explosion in New York City, all roads seem to lead to the world beneath the sidewalks.

The eruption sent steam sky high, swallowing the street and opening a window into a rarely seen part of New York — the subterranean city, hidden from view, but very much a part of everyday life.

In the dark underworld lies a labyrinth of pipelines, more than 100 miles long, they're mostly steam pipes, some laid over a century ago, by intrepid men, known at the time as "sandhogs."

In certain places, steam tunnels run as deep as the skyscrapers run tall, and when you are close, you can feel and hear the power — it's the sound of forced steam. The steam travels through the pipes at 200 pounds per square inch, at more than 275 degrees, so hot that in this tunnel it's well more than 100 degrees.

The subterranean tunnels have long been the topic of myth and legend, and tales of the people who dwell there, the so-called "mole people" often documented in Hollywood films like "Dark Days" and "Die Hard With a Vengeance."

But it's more function than fantasy. In New York, the steam is used for heating the tallest buildings, and energizing everything from dry cleaners, to hospitals.