Photo Release: Workers lower dome in water

GULF OF MEXICO - Crewmembers aboard the motor vessel Joe Griffin look on as the mobile offshore drilling unit Q4000 lowers a pollution containment chamber May 6, 2010. The chamber was designed to cap the oil discharge that was a result of the Deepwater Horizon incident. U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley. GULF OF MEXICO - Oil washes onto the sides of a pollution containment chamber as the mobile offshore drilling unit Q4000 lowers it into the water at the Deepwater Horizon site, May 6, 2010. The chamber was designed to cap the oil discharge that was a result of the Deepwater Horizon incident. U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley. GULF OF MEXICO - The mobile offshore drilling unit Q4000 lowers a pollution containment chamber into oily water at the Deepwater Horizon site May 6, 2010. The chamber was designed to cap the oil discharge that was a result of the Deepwater Horizon incident. U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley. GULF OF MEXICO - The mobile offshore drilling unit Q4000 lowers a pollution containment chamber May 6, 2010. The chamber was designed to cap the oil discharge that was a result of the Deepwater Horizon incident. U.S. Coast Guard photo by Petty Officer 3rd Class Patrick Kelley.