With 15,000 barrels of oil pouring in the gulf each day and the primary measures of using underwater subs to stop the oil have failed, BP changes strategy bringing in some brute force in the form of a giant concrete and steel dome.
The dome will basically sit over the well on the ocean floor and stop the leak. A relief spout attached to the dome will allow BP to pump the oil to an awaiting tanker floating overhead.
This is not a long term solution, BP is already drilling a secondary well to ease the pressure of the first. So the company can create a more permanent solution.