News sources have just reported that the oil spill in the Gulf of Mexico is spreading out of control and now threatens to eclipse the 1989 Exxon Valdez accident, which leaked 11 million gallons of oil into Alaska's Prince William Sound.

The massive oil spill in the Gulf of Mexico, which started when an offshore oil rig exploded, caught fire and sank, has reached the ecologically fragile Louisiana coastline and the mouth of the Mississippi River. The spreading oil is threatening marshlands along the Louisiana coast and 10 wildlife management areas in Louisiana and Mississippi as well as oyster, shrimp and other seafood fisheries in the Gulf of Mexico.

Government officials said late Wednesday that oil from the underground well could be leaking five times faster than previously estimated--at a rate of 5,000 barrels a day instead of 1,000. Emergency crews tried to corral the oil spill with skimmers and containment booms, and started a controlled fire to burn as much oil as possible off the surface of the water. Weather prevented additional burns on Thursday, but more burns are likely to be conducted when weather conditions improve.

Homeland Security Secretary Janet Napolitano on Thursday morning pronounced the incident a "spill of national significance," a designation that frees more federal resources to help with the cleanup. Later in the day, President Barack Obama dispatched Napolitano, Interior Secretary Ken Salazar and EPA Administrator Lisa Jackson to help with the spill and promised that the White House would use "every single available resource" to respond to what is almost certain to become the nation's worst oil spill and one of the most damaging environmental disasters in U.S. history.

"It is of grave concern," David Kennedy of the National Oceanic and Atmospheric Administration told The Associated Press. "I am frightened. This is a very, very big thing. And the efforts that are going to be required to do anything about it, especially if it continues on, are just mind-boggling."

Experts believe it could take up to three months to drill a relief well and plug the gushing oil well that lies 5,000 feet underwater. That well taps into one of the largest U.S. oil reserves and could continue pumping out 5,000 barrels (about 200,000 gallons) of oil per day until the repairs are done.

The oil spill also could have far-reaching effects on America's future energy policies, according to White House officials and other observers. President Obama's proposal to expand offshore oil and gas exploration and drilling along the Atlantic coast, the Gulf of Mexico and northern Alaska is about to enter a public comment period. White House Press Secretary Robert Gibbs said that public reaction to the oil spill might force modifications to the plan. Meanwhile, the comprehensive Senate Climate Bill, which also calls for expanded offshore drilling, may have an even tougher time garnering the votes needed for passage.

"This will become part of the debate" over offshore oil drilling, said Carol Browner, Obama's top energy and climate advisor. "That goes without saying."