Deepwater Horizon: 'Top Hat' install in progress

GULF OF MEXICO -- A pollution containment chamber, known as the "top hat", is lowered into the Gulf of Mexico by the motor vessel Viking Poseidon, May 11. The chamber will be used in an attempt to contain the oil leak that was caused by the mobile offshore drilling unit Deepwater Horizon explosion. 

Photo by Petty Officer 3rd Class Patrick Kelley

05/12/2010