The U.S. Coast Guard says the flow of oil and gas from the broken well in the Gulf of Mexico has been stopped by pumping mud into it, but the challenge will be whether that can be sustained.
Coast Guard commander Admiral Thad Allen told ABC's "Good Morning America" program that the next 12 to 18 hours will be "very critical" in the effort to stop the gusher, which has sent hundreds of thousands of barrels of oil
into the sea.
Energy giant BP's chief executive, Tony Hayward, said the effort to plug the well was "going pretty well according to plan" and that they planned to begin pumping more mud into the well again later today.
BP said its costs in responding to the massive oil leak have risen to about $930 million.
Scientists have confirmed the oil spill is the biggest ever in United States history.compiled from agency reports