Associated Press: A mission to the sea floor to try to avert a wider environmental disaster following the Deepwater Horizon oil spill made progress today as crews said a 100-tonne concrete-and-steel box was close to being placed over a blown-out well on the Gulf floor in an unprecedented attempt to contain the gushing oil. Douglas Peake, the first mate of the supply boat that brought the box to the site, confirmed that a radio transmission from the nearby vessel lowering the device said it would soon …