Gulf Crews Prepare to Lower Containment Dome

Crews prepared today to lower a 100-ton box they hoped would cut off most of the crude spewing from a blown-out well in the Gulf of Mexico, the urgency of their task underscored by oil that started washing up on delicate barrier islands. If the concrete-and-steel box works, it could collect as much as 85% of the leaking oil. Workers hope to have the device on the seabed this evening, but it will likely be Sunday or Monday before it's fully operational and they know if it's working.

More than 200,000 gallons of oil a day is pouring from the well, creating a massive sheen that's been floating on the Gulf for more than two weeks. Today, a pinkish oily substance was lapping at the shore of New Harbor Island, washing into thick marsh grass. It looked like soggy cornflakes, possibly because it was mixed with chemicals that it had been sprayed to break it up before it reached land.

(More Deepwater Horizon stories.)