Operated by the oil company BP, the Deepwater Horizon was an offshore drilling rig in the Gulf of Mexico that could drill deep beneath the seabed’s surface. In April 2010, an explosion occurred on the rig due to a blowout (uncontrolled release of crude oil after a mechanical failure on the rig), which resulted in the deaths of 11 crew members and a fireball that was visible from 40 miles away. The fire itself was extremely difficult to put out. The rig sank, leaving oil gushing from the seabed and resulting in the greatest oil spill in the ocean to date.

It took 87 days to seal the wellhead. BP used the oil dispersant Corexit. Corexit does not remove oil from the oceanwater. Instead, it breaks down the oil into small drops, making it more difficult for the oil to come back together and form large oil slicks on the surface. Oil droplets are also less likely to stick to marine life, birds, and the shoreline. Nixon suggests based on evidence that Corexit is highly toxic.

At least 4 million barrels of oil flowed into the ocean during this time, destroying marine life and polluting the Gulf. The US Congress expects BP to pay $34 billion in compensation for the spill.