[conservative in nyc]

Here's a picture of the damage:


And here are some Italians standing in front of the damage for you:

[Red Badger]

The Italians look PhotoShopped in..........but then that's normal for Italians........

[dfwgator]

Where's Green Helmet Guy?

[AnAmericanMother]

I've been involved in the investigation of numerous fires, including natural gas explosions, and the damage in the photos looks like a classic NG explosion. Ignition of the gas blew the walls out nearest the leak (that, or just the windows and doors if it's a smaller explosion, are the weakest points where the combustion gases will escape).

Sometimes you get a complete collapse as a result of the removal of the lateral support, but in this case it looks like the building was strong and redundant enough to survive the blowout.