The steam comes up through the street like the city is breathing. A crack in the asphalt and a white cloud rises and disappears and you walk through it and for one second you are inside the city's lungs. New York runs on steam. A hundred and five miles of pipe under Manhattan carrying steam from the power plants to the buildings and some of it leaks through the street and that is the most beautiful infrastructure failure in the world.

In the winter the steam pipes saved your life. You stood over a grate or a crack in the sidewalk where the steam came up and for thirty seconds you were warm. The homeless knew every steam vent in the city. They mapped them the way a prospector maps gold deposits. This one on Third Avenue runs hot all night. That one on Twenty-Third dies at midnight. The one on Bowery is good but the cops move you. The steam pipe was the city's radiator and it heated everybody who knew where to stand.

Con Edison puts orange and white barrels around the steam vents. The barrels have a pipe that goes up fifteen feet and the steam shoots out the top like a factory smokestack. Those barrels have been in the same intersections since I was young. They are the most permanent temporary structures in New York City. They were supposed to be there for a week. That was 1962. Nobody moved them. Nobody will move them. The barrel is part of the block now. It has seniority.

A steam pipe exploded on Lexington Avenue in 2007. Shot a geyser of steam and debris two hundred feet in the air. One person died. A crater in the middle of Manhattan like a volcano opened up under a taxi cab. The pipes are old. Cast iron. Laid down in 1882 when they built the system. A hundred and forty years old and still carrying steam. That is the thing about New York. The infrastructure is ancient and it works until the day it does not and then it explodes and somebody fixes it and it works again for another forty years.

You cannot see the steam in the summer. It is still there. The pipes are still running. The city is still breathing. But the air is too warm to show it. The steam only becomes visible when the cold air hits it. That is a metaphor for everything that matters. The work is always happening. You only see it when conditions are right. The city runs on invisible systems and invisible people and invisible labor and once in a while on a cold morning in January you see a white cloud rising from a crack in the street and you remember that something enormous is happening underneath you. Then you keep walking.