BP (British Petroleum) is an international oil company. In Deepwater Horizon, BP has provided drilling to Transocean, concrete and insulation work to Halliburton. British Petroleum was a main investor (parent company) in Mexico gulf. Transocean and Halliburton were its subsidiary. Transocean and Halliburton provided BP with information, but decisions were always made by BP based on these informations. So all three stakeholders were both sender and reciver at the same time. BP and its subsidiaries communicated mostly by e-mail and telephone. After the explosion, all e-mails were given to the investigative commission.1 A communication channel is the medium, mean, manner or method through which a message is sent to its intended receiver. The basic channels are written (hard copy print or digital formats), oral or spoken, and electronic and multimedia.2 Even if business units operate largely on a decentralized basis, they must keep the head office informed, especially with regard to strategic decisions. Even the individual units have to keep each other informed if they are working on the same project. In view of this, communication is extremely important. Transocean, for example, had to constantly pass on information to BP (e.g. concentrates that the well needs). Halliburton was also asked to discuss the chemical composition of the concrete with BP in order to select a suitable and effective composition for the well. BP itself analyzed the information received from both parties and expressed its views on the matter and passed on its decisions to Transocean and Halliburton. For Halliburton and Transocean, the communications were also essential (e.g. in order to achieve a suitable chemical composition of the concrete, Halliburton needed samples of well bottoms). Intrapersonal Communication means the person with himself, for example, a person (Miles Randy Ezell) on Deepwater Horizen was supposed to get a better job after the end of the drilling and he had tried logically to analyze everything that leads to the end. Most of the time we see things the way we want to see not the way it is," Prof. Robert Bea. Small Group Communication: e.g. drilling team among themselves. 11 people who were in the drill rig. Organizational Communication: Communication between BP engineers and drilling team. Mass Communication: management conference and announcement that drilling is successfully completed (approximately 2-3 hours before the explosion)3 1 https://www.youtube.com/watch?v=RfZXPlvmc7Y&ab_channel=StevenLord https://courses.lumenlearning.com/wm-principlesofmanagement/chapter/channels-of-businesscommunication/#:~:text=Business%20Communication%20Channels&text=A%20communication%20c hannel%20is%20the,spoken%2C%20and%20electronic%20and%20multimedia 3 https://www.youtube.com/watch?v=RfZXPlvmc7Y&ab_channel=StevenLord 2