The burning oil was contained by a length of boom. The BP oil spill began when the Deepwater Horizon rig suffered an explosion on April 20, 2010. The burning oil was contained by a length of boom. A “blowout” on an oil rig occurs when some combination of pressurized natural gas, oil, mud, and water escapes from a well, shoots up the drill pipe to the surface, expands and ignites. Deepwater Horizon Oil Spill: How Officials Are Working to Prevent Another Tragedy Today marks six years since the oil spill. It was a result of the well blowout that began with the Deepwater Horizon drilling rig explosion on April 20, 2010. Of the 126 workers at the site that day, 11 were killed by the blast. Within days of the April 20, 2010 explosion and sinking of the Deepwater Horizon oil rig in the Gulf of Mexico that killed 11 people, underwater cameras revealed the BP pipe was leaking oil and gas on the ocean floor about 42 miles off the coast of Louisiana.

Oil-eating microbes have consumed a considerable portion of the Deepwater Horizon oil spill. A man surf fishes as the sun rises, days after BP announced it is ending its active cleanup on the Louisiana coast from the Deepwater Horizon oil spill, on April 19, 2014, in Grand Isle, La. It was a massive oil spill in the Gulf of Mexico, the largest offshore spill in U.S. history. Deepwater Horizon oil spill, also called Gulf of Mexico oil spill, largest marine oil spill in history, caused by an April 20, 2010, explosion on the Deepwater Horizon oil rig—located in the Gulf of Mexico, approximately 41 miles (66 km) off the coast of Louisiana—and its subsequent sinking on April 22. Various species of dolphins and other mammals (61 casualties), birds (2,095 casualties), and the endangered sea turtles (467 casualties) have been killed either directly or indirectly by the oil spill.

Deepwater Horizon oil spill: controlled burn Controlled burn of oil spilled in the Deepwater Horizon disaster, Gulf of Mexico, May 6, 2010.

Deepwater Horizon oil spill stopped, says BP BP said that the cap over the oil well has completely stopped the spill, with no oil leaking into the Gulf of Mexico. Fire boats battle the fire on the oil rig Deepwater Horizon after the April 21 explosion. The Gulf spill is no exception.

Efforts to stem the Deepwater Horizon oil spill were ongoing from the time that the Deepwater Horizon exploded on 4/20/2010 until the well was sealed by a cap on July 15, 2010. The Gulf oil spill is recognized as the worst oil spill in U.S. history. In its first month, BP spilled 30 million gallons of oil into the Gulf, three times the Exxon Valdez oil spill.