It is now more than two weeks since the BP oil rig exploded 67 kilometres off the Louisiana coast.
Since then an estimated 200,000 gallons of oil a day has been spewing into the sea.
It is the biggest oil spill since the Exxon Valdez disaster in 1989 and many fear that the consequences of this one could be even worse.
The first reports have come in that the oil had closed in on the delicate Chandelier Islands off the Louisiana coast.
The group of islands forms a natural barrier between the Gulf and the Mississippi Delta wetlands.
Late on Friday BP engineers were directing underwater robots to position the huge purpose-built concrete dome over the leak 5,000 feet below the surface.
It may take some days to know for sure if the capping operation works.
Department of Homeland Security secretary Janet Napolitano says she is not overly optimistic.
“I hope it works. It has not been used at that depth before, but we are still proceeding as if it won’t,” she said.
“If it does that of course will be major positive development.”
Fishing disaster
Small boats have been laying boom out there since the spill began in the hope that the oil can be stopped before it reaches the sensitive marshes, the breeding areas for one of the country’s most fertile fishing grounds.
Stan Cuhanovic, who first came to the Louisiana from Croatia in 1971, has been working this part of the gulf ever since.
Out in the bay he punched in the coordinates on his on board satellite navigation system and spelt out the consequences should the oil breach the islands.
“Very productive fishing areas. Oysters, they’re growing by itself – you don’t have to do anything to them,” he said.
“If this area is ruined it would be devastating for the oyster people.”
Fishing is a huge industry in Louisiana and although no-one quite knows what the impact of the spill will be, many are expecting the worst.
This disaster will change life for everyone, but until now most people there had embraced the oil industry as part of the fabric of life in the gulf.
As Stan Cuhonavic tells it, many here worked in both industries.
“A lot of people who are doing the part time fishing, they work in oil field on their day off,” he said.
“They use their small shrimp boat and they go trawling and catching the shrimp.”
Even if the cap works no-one here thinks the crisis is over.
In the short-term, more oil exploration in the gulf is highly unlikely and many fear it could take decades for the fishing to recover.
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