There's conflicting reports as to whether it was a steampipe or a transformer, but something left a crater in the street.

It's amazing how many friends I had nearby to this explosion.

This happens all too often in NYC. My dad worked on Maiden Lane, down from the (former) WTC and Battery Park, and he was always telling me of these types of explosions - one of which he witnessed from half a block away.

As long as there is steam under tremendous pressure right under the streets of NYC, there will continue to be these explosions, with injuries and death from debris and flying man hole covers.