Deepwater Horizon Oil spill. Oil soaked Pelican on Island in Barataria Bay coast of Louisiana 5 23 2010
President Barack Obama and LaFourche Parish President Charlotte Randolph show small amounts of oil washed up as "tar balls" during a tour of areas impacted by the Gulf Coast oil spill,Friday, May 28, 2010, in Port Fourchon, La. (AP Photo / Evan Vucci)
BP kept pumping heavy mud into its blown-out well beneath the Gulf of Mexico on Friday May 28, 2010, but the company's chief executive cautioned it will be two more days before anyone knows if the latest fix attempt will end the uncontrolled flow of crude that has already become the worst oil spill in U.S. history.
The top kill is oil and gas giant BP PLC's latest untested bid to end the spill that has, by the most conservative estimate, surpassed the Exxon Valdez disaster by gushing more than 18 million gallons into the Gulf.