The shriek of Katrina’s 140 mph winds and rat-a-tat-tat of its driving, torrential rain left in its tumultuous wake a coast silenced by vast devastation. Darkness ruled not just night but day, as the electric grid crash darkened shelters and the lights of fiber-optic cable went off in an instant. Cell towers fell, broadcast stations were yanked off the air, and the voices of a great city fell silent. The city, and parts of the Gulf Coast as well, simply dropped off the globally networked web of voice, data and video communications that define societal participation in the Information Age. The sounds that most often reached one’s ears, besides the voices of reporters talking into portable microphones, were those of whirring helicopter blades and episodic cracks of gunfire.