The Deepwater Horizon oil spill occurred in 2010.
The disaster began on 20 April 2010 in the Gulf of Mexico at BP’s Macondo prospect. High-pressure methane reached the Deepwater Horizon drilling rig, triggering explosions and a fire. Eleven workers died, 17 were injured, and the rig sank on 22 April. Oil continued flowing from the damaged well for roughly 87 days.
A containment cap stopped the main flow on 15 July, and relief wells were used to seal the well permanently. The well was declared effectively sealed on 19 September 2010. The United States government estimated that approximately 4.9 million barrels of oil entered the Gulf, making it the largest accidental marine oil spill associated with petroleum production.
People sometimes use “Deepwater Horizon” to mean the rig, the explosion, or the spill. The rig was the drilling unit; the spill was the prolonged release from the Macondo well after the blowout. The event caused extensive damage to Gulf ecosystems, fisheries, coastal wetlands, tourism, and wildlife.