A welder at work on a piece from the Pol

A welder at work on a piece from the Pollution Control Dome (behind) being built by steelworkers at the Martin Terminal worksite in Port Fourchon, as BP rushes to cap the source of the oil slick from the BP Deepwater Horizon platform disaster in Louisiana, on May 3, 2010. Using remote-controlled submarines to shut off the leaking oil well in the Gulf of Mexico is like doing "open heart surgery at 5,000 feet in the dark," the head of BP's US operations said. BP America Chairman and President Lamar McKay acknowledged that the oil gushing from the fractured well nearly a mile (1,500 meters) below the ocean surface was due to a defective equipment designed to shut down the well in a blowout. Six robotic submarines struggled to activate a 450-tonne blowout preventer valve that failed to work properly when the well exploded April 20, igniting a fire that sent the Deepwater Horizon rig to the ocean floor with 11 workers missing and presumed dead. AFP PHOTO/Mark RALSTON (Photo credit should read MARK RALSTON/AFP via Getty Images)