National Public Radio: The Coast Guard Wednesday started a test burn of an area about 30 miles east of the delta of the Mississippi River to see how a plan to burn up an oil spill before it could wash ashore and wreak environmental havoc was working. Crews turned to the plan after failing to stop a 1,000-barrel-a-day leak at the spot where a deepwater oil platform exploded and sank. A 500-foot boom was to be used to corral several thousand gallons of the thickest oil on the surface, which will then be towed …