Coast Guard Adm. Thad Allen says BP has successfully sliced off a pipe in an effort to contain the Gulf oil, but the cut is irregular and placing a cap over the spill will be more challenging.
Allen said Thursday that the cap was over the gusher and expected to be lowered in the next couple of hours.
This is BP's latest attempt to contain the oil. The best chance to plug the leak is still two months away.
BP says it was about halfway done slicing through the pipe when the diamond-tipped saw snagged. It took BP 12 hours to free it. The company said it hoisted the saw back to the surface after it finally yanked it out of the pipe.
The Coast Guard is not sure exactly why the saw failed.
Meanwhile, a doctor says 11 workers who have been out on the Gulf of Mexico cleaning up oil from BP's blown-out well have been treated for symptoms that could be related to the oil.
Dr. Damon Dietrich says he has seen patients come through his emergency room at West Jefferson Medical Center with respiratory problems, headaches and nausea.
All were treated and released.
He says 11 people coming in with the same symptoms make him suspicious.
BP and U.S. Coast Guard officials have said dehydration, heat, food poisoning or other unrelated factors may have caused the workers' symptoms. The Louisiana Department of Health and Hospitals is investigating.
On Friday, the White House says President Barack Obama will return to the Louisiana Gulf Coast to assess the latest efforts to counter this spill.
This will be Obama's third trip to the region since the April 20 accident that started the spewing of oil in the area, and it's his second visit in a week. The incident is now considered the worst oil spill in U.S. history.
The White House says more details on Friday's trip will be released later in the day.
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