The Deepwater Horizon oil spill (also referred to as the BP oil spill, the BP oil disaster, the Gulf of Mexico oil spill, and the Macondo blowout) was an oil spill in the Gulf of Mexico on the BP-operated Macondo Prospect, considered the largest accidental marine oil spill in the history of the petroleum industry. Following the explosion and sinking of the Deepwater Horizon oil rig, which claimed 11 lives, a sea-floor oil gusher flowed unabated for three months in 2010. The gushing wellhead was not capped until after 87 days, on 15 July 2010. The total discharge is estimated at 4.9 million barrels (210 million US gal; 780,000 m3).
A massive response ensued to protect beaches, wetlands, and estuaries from the spreading oil, using skimmer ships, floating boom, controlled burns, and 1.84 million US gallons (7,000 m3) of Corexit oil dispersant. After several failed efforts to contain the flow, the well was capped and declared sealed on 19 September 2010. However, the months of spill, along with response and cleanup activities, caused extensive damage to marine and wildlife habitats and the Gulf’s fishing and tourism industries, as well as human health problems. Environmental and health consequences are continuing, with study and investigation ongoing. Some reports indicate the well site may be continuing to leak.