An accident investigation is an attempt to discover the cause of an accident and any related contributing factors. Sometimes the investigation is carried out in order to assign legal fault to a person for purposes of a lawsuit. In certain types of accidents, government agencies conduct the investigation for the dual purpose of finding the cause of the accident and preventing future ones. Most countries have specific administrative agencies that carry out these kinds of investigations.
These types of investigations are frequently done in serious car accidents in both civil and criminal cases. Accident investigations usually involve investigators with expertise in crash reconstruction who have been hired by a party to a lawsuit. They often have engineering backgrounds and practical experience in the field. They write reports detailing the factors they used in coming to their conclusions, and can testify about causation in court proceedings. In cases involving criminal charges, law enforcement agencies sometimes use their own trained investigators.
In cases involving accidents in the area of public transportation, federal agencies like the National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA) conduct an accident investigation. In accidents involving commercial airliners, where there is potential for multiple fatalities and serious injuries, the FAA and NTSB work together in determining the cause of the crash. Investigative teams comprised of experts from different specialties examine all the systems involved, including human performance and flight control assistance to determine a cause.
Both the FAA and NTSB include their accident reports and summaries of their investigations on an Internet site available to the public. The data from these reports and summaries is analyzed for patterns or common occurrences. The agencies hold public hearings on the results of their investigations and seek public input on preventive measures. In the UK, Air Accidents Investigations (AAI) performs similar functions.
The US Occupational Safety and Health Administration (OSHA) performs accident investigation in the workplace and at worksites. It looks for safety failures in equipment, supplies, people, and the work environment to determine the cause of accidents. OSHA also sets safety standards for many occupations and issues regulations for workplace conditions. Its investigative reports contain conclusions about the cause of the accident and recommendations for preventing future occurrences.
OSHA offers a guidebook for employers on how to conduct their own job hazards analyses. The agency also maintains a database of accident statistics that is available to the public. It conducts hearings on the conclusions of its accident reports and any proposed regulations resulting from the reports.