(AP) - Timeline of the massive 2010 Gulf of Mexico oil spill, government response and ensuing legal cases:
_ April 20, 2010: An explosion and fire on the BP-operated drilling rig Deepwater Horizon kill 11 workers about 50 miles off the Louisiana coast. The rig sinks less than two days later; crude oil begins gushing into the Gulf from the blown-out Macondo well about a mile below the Gulf surface. Before the well is capped, an estimated 200 million gallons of oil escape.
_ April 29, 2010: President Barack Obama makes his first public statement about "the worsening oil spill." He pledges "every single available resource" to contain the slick, including Pentagon assistance if necessary. Oil from the well makes landfall near the mouth of the Mississippi River. Over several months, sensitive marshlands and fishing grounds across the northern Gulf coast are fouled.
_ May 14, 2010: Then-BP CEO Tony Hayward says the amount of spilled oil is relatively small given the size of the Gulf. "The Gulf of Mexico is a very big ocean," he says. "The amount of volume of oil and dispersant we are putting into it is tiny in relation to the total water volume."
_ May 28, 2010: Hayward says the "top kill" effort to plug the well with mud is progressing as planned and has a 60 to 70 percent chance of success. The next day the company announces the effort has failed.
_ May 30, 2010: Hayward shocks Gulf residents when he says "I'd like my life back," an apparent reference to the intensity of dealing with the spill. He also disputes scientists' claims that there are large plumes of oil under the Gulf surface.
_ June 16, 2010: BP agrees to put $20 billion into an escrow fund to settle economic injury claims by fishermen and various Gulf industries.
_ June 22, 2010: A federal judge strikes down the Obama administration's six-month ban on deepwater drilling in the Gulf, saying the government rashly concluded that other rigs could be in immediate danger.
_ July 1, 2010: Based on the high end of government estimates, the spill surpasses the 140-million-gallon mark. That eclipses the 1979 Ixtoc disaster in the southern Gulf and means the BP spill now ranks as the biggest offshore oil spill during peacetime.
_ July 15, 2010: After 85 days, BP manages to stanch the leak with a massive cap. The cap holds until a more permanent solution is put into place.
_ July 26, 2010: BP says Hayward, who is British, will step down on Oct. 1 and be succeeded by American Robert Dudley. BP said it planned to recommend Hayward for a non-executive board position at its joint venture in Russia.
_ September 19, 2010: Federal officials say the well has been permanently sealed after workers drill a relief well into the damaged one and insert a cement plug.
_ October 12, 2010: Obama's administration lifts the six-month moratorium on deepwater oil drilling in the Gulf. Interior Secretary Ken Salazar says new rules imposed after the BP spill have strengthened safety measures.
_ December 15, 2010: The Justice Department files suit against BP and eight other companies over the accident, asking they be held liable for removal costs and damages caused by the explosion and spill.
_ January 12, 2011: A 380-page report from government-appointed National Oil Spill Commission finds that time- and money-saving decisions created an unreasonable amount of risk that triggered the Deepwater Horizon explosion.
_ March 2, 2012: BP and lawyers for residents and businesses that said they were hurt by the spill reach a settlement before the trial begins. Tens of thousands of people waiting for money from a fund managed by Kenneth Feinberg, the Gulf Coast Claims Facility, can take what the settlement offers them or opt out and make a claim directly to a BP-run entity. They can file suit if they don't like what they get from that fund.
_ November 15, 2012: BP agrees to pay $4.5 billion in a settlement with the U.S. government and to plead guilty to felony counts related to the deaths of 11 workers and lying to Congress. The figure includes nearly $1.3 billion in criminal fines- the largest such penalty ever- along with payments to several government entities. Two BP well site leaders are charged with manslaughter, and a former executive is charged with lying to authorities.
_Jan. 3, 2013: The Justice Department reaches a $1.4 billion settlement with rig owner Transocean Ltd. The deal requires the Switzerland-based company to pay $1 billion in civil penalties and $400 million in criminal penalties and plead guilty to a misdemeanor charge of violating the Clean Water Act.
_ Jan. 29, 2013: A federal judge approves the settlement between the U.S. government and BP.
_ Feb. 14, 2013: A federal judge approves Transocean Ltd.'s agreement with the Justice Department.
_ Feb. 25, 2013: Opening statements begin in a high-stakes trial to determine the cause of the well blowout that led to the spill and assign percentages of blame to BP and other companies involved. Billions of dollars are at stake.
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