On Thursday, a manageable explosion on a Gulf Coast oil rig reignited fears founded by the BP spill and revived calls for a reassessment of the country's drilling policies.

Just before 9 a.m. Thursday morning, the Vermilion Oil Rig 380 exploded. Unlike the Deepwater Horizon rig, this one was located in shallow waters. By late afternoon, a sheen of oil had been spotted, spreading a mile long from the burning rig; but by Friday morning the Coast Guard was saying the that was a mistake -- there was no sheen.