 On April 20, 2010, the "Deepwater Horizon" drilling rig, located in the MMS Mississippi Canyon block 252, which is about off the Louisiana coast, suffered a catastrophic explosion; it sank a day-and-a-half later.Although initial reports indicated that relatively little oil had leaked, by April 27 it was stated by BP that approximately of oil per day were issuing from the wellhead, below the surface on the ocean floor.The resulting oil slick quickly expanded to cover hundreds of square miles of ocean surface, posing a threat to marine life and adjacent coastal wetlands.