A man holds a plastic bag with oil from the Gulf of Mexico oil spill south of Freemason Island, Louisiana May 7, 2010. BP Plc engineers using undersea robots maneuvered a massive metal chamber to fit over a gushing ruptured oil well in the Gulf of Mexico on Friday in their best chance yet to contain a leak that threatens an environmental catastrophe on U.S. shores. REUTERS/Carlos Barria (UNITED STATES - Tags: DISASTER ENERGY ENVIRONMENT IMAGES OF THE DAY)