Timeline of the Deepwater Horizon oil spill Timeline of the Deepwater Horizon oil spill The following is a timeline of the "Deepwater Horizon" oil spill (also referred to as the BP oil spill, the Gulf of Mexico oil spill or the Macondo blowout). It was a massive oil spill in the Gulf of Mexico, the largest offshore spill in U.S. history. It was a result of the well blowout that began with the "Deepwater Horizon" drilling rig explosion on April 20, 2010. BP reports a leak a day. DeepWaterHorizonResponse.com domain registered for one year by PIER Systems in Bellingham, Washington to be used by the United States
Volume and extent of the Deepwater Horizon oil spill collected before it could enter the Gulf waters. In its permit to drill the well, BP estimated the worst-case flow at . Immediately after the explosion the USCG did not estimate any oil leaking from the sunken rig or from the well. On 24 April, USCG Rear Admiral Mary Landry announced that a damaged wellhead was indeed leaking. She stated that "the leak was a new discovery but could have begun when the offshore platform sank . . . two days after the initial explosion." Initial estimates by USCG and BP officials, based on remotely operated vehicles as well as