Oil rig explosion

NEW ORLEANS, April 30 (UPI) -- Oil from a rig that sank 50 miles from shore has reached the Louisiana coast, threatening the environmentally sensitive wetlands of the Mississippi River delta.

Crude oil from the well once attached to the Deepwater Horizon platform escaped the wellhead at an estimated 5,000 barrels -- 210,000 gallons -- a day. A huge slick coated hundreds of square miles of the surface and southwesterly winds pushed the oil toward shore.

Officials said by late Thursday oil could be seen at the delta, which is home to thousands of species of wildlife and near areas important to the gulf fishing industry.

State and federal authorities took steps to prepare for a potential disaster that could rival the impact of the Exxon Valdez spill of 11 million gallons of oil crude oil in Alaska in 1989.

BP, the oil company that operated the Deepwater Horizon, employed a series of efforts to address the emergency, including chemical dispersants and hundreds of thousands of feet of booms to try to corral the oil. The U.S. Coast Guard tried a controlled burn of some of the surface oil Wednesday. BP is also working to shut the flow off at the source, a wellhead about 1 mile below the surface.

An explosion on the Deepwater Horizon rig April 20 caused a huge fire on the platform, which collapsed and sank two days later. Most of the onboard workers were evacuated but 11 people are missing and presumed dead.