The mobile offshore drilling unit Q4000 holds position directly over the damaged Deepwater Horizon blowout preventer as crews work to plug the wellhead using a technique known as "top kill," May 26, 2010. The procedure is intended to stem the flow of oil and gas and ultimately kill the well by injecting heavy drilling fluids through the blow out preventer on the seabed down into the well. A nearby vessel sprays sea water near the surface of Q4000 to keep oil and fumes from interfering with operations. (U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley)
