It occurred after an explosion on the Deepwater Horizon rig.
A vast amount of the emulsifier Corexit was used in the aftermath of this event. Kurt Mix was charged for his role in this event, after deleting hundreds of voicemails about operation "top kill."  Tony Heyward was castigated for asking if he could "have [his] life back" during its fallout. This event, which occurred 21 years after a similar event at Ixtoc I, was blamed on contractors for (*) Halliburton and Transocean. During this event, a cement cap failed to prevent the wellhead blowout at the Macondo Prospect. It occurred after an explosion on the Deepwater Horizon rig. For 10 points, name this 2010 environmental disaster in the Gulf of Mexico.
A vast amount of the emulsifier Corexit was used in the aftermath of this event.
BP oil spill [or British Petroleum oil spill; or the Gulf of Mexico oil spill; or the Deepwater Horizon explosion until it is read; or the explosion at the Macondo Prospect until it is read; accept any answers that mention oil spilling AND either the location or the company responsible]