This study investigates the root causes of the Macondo well blowout in the Gulf of Mexico in 2010. It is based mainly on the National Commission on the British Petroleum Deepwater Horizon Oil Spill report released in 2011. The different resources were thoroughly analyzed and data were accurately collected in preparation for the fishbone diagram. In addition to generating a unique data record for this accident, which can be used for future improvements within the industry, the study highlights the contribution of each individual factor utilizing a series of simple yet effective total quality management tools. Giving to the considerable number of factors contributed to the accident, regardless of their degree of involvement, based on the fish bone diagram, an experienced team was formed to downsize and pinpoint the key factors led to the disaster. According to study findings and team analysis, ineffective risk assessment, untested contingency plans, lack of horizontal integration, last minute design changes, individual based decision making and other reasons accumulated causing the disaster. This work proofs that management is a system which needs to be maintained and updated, so such accident can be avoided.