Roughly 20 years after the Exxon Valdez oil spill, the largest accidental marine oil spill in history occurred in the U.S. Gulf of Mexico. This disaster took place in April 2010 when an oil well on BP's Deepwater Horizon rig exploded. The Deepwater Horizon oil spill claimed 11 lives and leaked 134 million gallons of crude oil into the Gulf. The spill harmed or killed thousands of marine species including sea turtles, whales, dolphins, birds, and fish. Oil flowed into the Gulf for 87 days before responders successfully capped the well in July 2010, and as of 2021, cleanup efforts are still ongoing.