What the heck's going on in New York

Apparently a lot of Manhattan, as I type this, smells like the chemical that power companies add to natural gas to make it smell like danger. I'm watching the CNN screen in the Grand Prix cafe now and they're going koo-koo over it, reporters standing on mid-town streets saying they can't really smell anything but have heard reports from all over about the smell.

There's apparently no indications of actually dangerous concentrations of combustible gas yet. But what a strange and interesting thing, to have your whole city smell like you need to disconnect its stove.