On the evening of April 20, 2010, Deepwater Horizon suffered a blowout while drilling in the Macondo Prospect, an area in the Gulf of Mexico 40 miles off the southeast coast of Louisiana. The platform caught fire; two days later, it sank. Numerous attempts were made to seal the well, but oil continued to spew into the Gulf until July 15, when a temporary cap was put in place. Relief wells then pumped concrete into the area underneath the wellhead, and the well was deemed permanently sealed in mid-September.