By Mark Memmott
Homeland Security Secretary Janet Napolitano just told reporters at the White House that the massive oil spill in the Gulf of Mexico off the Louisiana coast has been declared an event of "national significance," which she said will allow the federal government to drawn on resources from across the nation to help try to head off a natural disaster as the slick nears shore.
The oil is coming from an undersea well damaged last week by an explosion that destroyed an oil rig -- and left 11 rig workers missing and presumed dead.
Napolitano also just emphasised that the oil company that was doing the drilling -- BP -- is responsible for the costs associated with the spill the clean-up.
Officials expect the oil will reach the Mississippi delta sometime tomorrow.