A massive crude-oil slick from an exploded rig in the Gulf of Mexico inched closer to the mouth of the Mississippi river late on Thursday as the government marshalled resources to protect fragile wetlands.
The estimated 5,000-sq-km slick was spreading faster than expected and could reach the shores of Louisiana as early as Thursday night. It could devastate fisheries, wildlife refuges, bird sanctuaries and tourism in Louisiana as well as Mississippi, Alabama and Florida.
The size and speed of the oil slick grew exponentially after energy giant BP Plc, which owned the Deepwater Horizon floating rig, which exploded, confirmed that its exploratory well in the Gulf of Mexico was gushing up to five times the amount of crude oil than had been originally estimated after last week's blast.
The National Oceanographic and Atmospheric Administration said the slick was expected to hit the east side of the Mississippi River Delta late on Thursday at Pass-A-Loutre, Louisiana, home to a bird sanctuary.
"While BP is ultimately responsible for funding the cost of response and cleanup operations, my administration will continue to use every single available resource at our disposal - including, potentially, the Department of Defence - to address the incident," President Barack Obama said Thursday.
Homeland Security Secretary Janet Napolitano declared the leak to be of "national significance", freeing up federal agencies to get involved.
Napolitano, Interior Secretary Ken Salazar and Environmental Protection Agency Administrator Lisa Jackson were to travel to Louisiana Friday to inspect efforts to contain the oil slick.
The estimated rate of leakage from the damaged well was raised to 5,000 barrels a day on Thursday, five times the 1,000 barrels a day previously feared to be spilling, BP said.
Salazar has ordered an "immediate inspection" of all deep-water drilling and pumping platforms in the Gulf of Mexico.
Doug Suttles, BP's chief operating officer for exploration, estimated that drilling a relief well, which would help pump heavy fluid into the well to counteract the pressure, "could take 90 days."
A siphoning alternative, which would funnel the gushing oil up a pipe to a drill ship, could take two to four weeks to build.
Obama had backed March 31 new drilling for oil and natural gas off parts of the US coastline as part of the solution to the country's massive energy needs. But the oil spill could now alter those plans.