If a desperate, last-ditch attempt to cap the Deepwater Horizon wellhead fails, environmental damage to the Gulf of Mexico may profoundly and permanently alter the area. “Thousands of miles of marshlands, sea-grass meadows and coral reefs—and the human industries they support—could be damaged beyond recovery. This is a worst-case scenario, and far from certain. But as long as the oil keeps flowing, the odds of it happening get better.”