Yesterday's explosion near Grand Central...

... took place just as I was finishing my shift. I posted immediately that at the time (7PM Estern), there were no injuries reported.

Unfortunately, this morning we know there was one death and 30 injuries, two of them critical. Considering the location - near 41st Street and Lexington Avenue - and the time of day, it is a miracle that it wasn't worse.

CNN and the BBC have photo slide shows, and they are all too reminiscent of the 9/11 images that are so engraved in our minds.

Fortunately, the explosion was not caused by an act of terrorism but by a steam pipe explosion, which have occured before

Manhattan is home to the largest district steam system in the world, according to the Web site of the city's Economic Development Corp. While most of the city's buildings have on- site boilers to provide heat during the winter, the Con Edison Steam Business Unit heats 1,800 buildings, serving more than 100,000 commercial and residential customers through a series of underground pipes running from the Bowery in lower Manhattan to 96th Street.

Consolidated Edison's steam network links many end-users to central power plants through a network of pipes carrying either steam or heated/cooled water under high pressure. The New York Steam Co. began providing such service in lower Manhattan in 1882.

In 2000, a steam pipe explosion near New York University's Bobst Library on Washington Square blew a 15-foot crater into the street on Washington Square South, and spewed debris and traces of asbestos into the air. The 1989 blast that killed three sent debris several stories into the air.

The 83-year-old pipe exploded just before 6PM, right in the middle of rush hour, when cold water reached the hot steam pipe.

The WaPo has video of the scene.

Ed Driscoll and Dan Riehl have more.