Official websites use .mil
Secure .mil websites use HTTPS
DEEPWATER HORIZON - Macondo Well Blow-Out
The Deepwater Horizon mobile offshore drilling unit (MODU) was performing drilling operations on the Macondo Well at Mississippi Canyon Block 252 on April 20, 2010 when a series of events led to an explosion and fire that tragically took 11 lives and injured 16 other personnel.
Our condolences go out to the families and friends of the 11 men that lost their lives in this casualty.
Deepwater Horizon was severely damaged and sank on April 22. The casualty resulted in the continuous flow of hydrocarbons into the Gulf of Mexico for 87 days before the well was capped, causing the largest oil spill in U.S. history, significant environmental damage to the Gulf of Mexico and personal and economic impact to communities all along the Gulf Coast.
This page serves to consolidate information related to the incident with access to the numerous reports generated by various government agencies and involved companies. All reports are credited to the respective agency or company and are readily available through linked sites or separate internet searches.
Use the tabs above to view investigation information by the following government agencies, involved companies and academia:
1) U.S. Coast Guard and Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) Joint Investigation Team (JIT)
2) U.S. Chemical Safety and Hazard Investigation Board
3) National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling
4) BP (Macondo Well Lessee)
5) Transocean (Owner/Operator of Deepwater Horizon; contracted by BP for Macondo Well work)
6) Republic of the Marshall Islands (Flag State Administration for Deepwater Horizon)
7) Deepwater Horizon Study Group (UC-Berkeley's Center for Catastrophic Risk Management)
Joint Investigation (U.S. Coast Guard & Bureau of Ocean Energy Management, Regulation and Enforcement)
The investigation into this incident was conducted by a joint investigation team consisting of members from the U.S. Coast Guard and the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE). The reports are accessible below, with excerpts from their respective executive summaries.
Excerpt from the Executive Summary: The Joint Investigation Team (JIT) comprised of members from the U.S. Coast Guard and Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) examined five aspects of this disaster relating to areas of responsibility of the U.S. Coast Guard: the explosions, the fire, the evacuation, the flooding and sinking of the MODU, and the safety systems of DEEPWATER HORIZON and its owner-operator, Transocean. Although the events leading to the sinking of DEEPWATER HORIZON were set into motion by the failure to prevent a well blowout, the investigation revealed numerous systems deficiencies, and acts and omissions by Transocean and its DEEPWATER HORIZON crew that had an adverse impact on the ability to prevent or limit the magnitude of the disaster...
Excerpt from the Executive Summary: This Report sets forth in detail the Panel’s investigative findings, conclusions, and recommendations. The Panel’s findings and conclusions are presented in the following subject areas: well design; cementing; possible flow paths; temporary abandonment of the Macondo well; kick detection and rig response; ignition source and explosion; the failure of the Deepwater Horizon blowout preventer; regulatory findings and conclusions; and company practices...
U.S. Chemical Safety Board
The U.S. Chemical Safety and Hazard Investigation Board report is available in multiple volumes that are available on their Macondo Blowout and Explosion page, as well as below for ready reference:
National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling
President Obama established the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling through Executive Order 13543 on May 21, 2010. The Commission was established to examine the relevant facts and circumstances concerning the root causes of the Deepwater Horizon oil disaster and develop options to guard against, and mitigate the impact of, oil spills associated with offshore drilling. This included recommending improvements to federal laws, regulations, and industry practices and organizational or other reforms of Federal agencies or processes necessary to ensure implementing and maintaining those improvements.
A final report on the Commission’s findings was presented to the President on January 12, 2011.
The Oil Spill Commission Action project is an outgrowth of the National Oil Spill Commission, to continue efforts to make offshore oil drilling safer by promoting the implementation of the recommendations of the National Oil Spill Commission. Additional information and National Oil Spill Commission documentation is available through the OSCA website.
Commission resources are as follows (linked below for ready reference and available through the OSCA Resource Center):
BP Incident Investigation Team
The BP Deepwater Horizon Accident Investigation Report (opens in a new window; contents summarized below) was published on September 8, 2010, using evidence that was available at the time and while many of the reports that were previously listed were in process.
In their report, the BP incident investigation team summarized breached barriers with the following graphic (image credit BP; Figure 1 on pages 32 and 181 of the linked BP report):
Transocean Investigation Report
The Transocean Macondo Well Incident Investigation Report is available in two volumes, as linked and summarized below. Additional information is available on Transocean's website by searching "Deepwater Horizon", "Macondo", or similar terms in their site search box.
Macondo Well Incident: Transocean Investigation Report, Volume I (opens in a new window; contents summarized below)
Macondo Well Incident: Transocean Investigation Report, Volume II (opens in a new window; Volume II contains appendices, as listed below)
Republic of the Marshall Islands
The Republic of the Marshall Islands (RMI) was the Flag State Administration of the Deepwater Horizon and published the RMI Investigation Report (opens in a new window) on August 17, 2011. The report contents are as follows:
Deepwater Horizon Study Group
The University of California, Berkeley's Center for Catastrophic Risk Management researched the incident and published their Final Report on the Investigation of the Macondo Well Blowout (opens in a new window). The report has the following content: