Associated Press: Coast Guard officials say an oil rig that exploded Tuesday off the coast of Louisiana could be spilling thousands of gallons of crude oil into the Gulf of Mexico. Officials previously had said the environmental damage appeared minimal, but when the rig sank Thursday that changed. The Coast Guard says the Deepwater Horizon carried 700,000 gallons of diesel fuel and could spill as much as 8,000 barrels of crude a day. Meanwhile, crews continued to search by air and water for 11 …