The Transportation Safety Bureau of Hungary (TSB, Hungarian: Közlekedésbiztonsági Szervezetet, KBSZ) is a government agency of Hungary, headquartered in Budapest. The created the agency on 1 February 2006. It investigates air, rail, and marine accidents. Prior to the creation of the TSB, the Civil Aviation Safety Bureau of Hungary (CASB, Hungarian acronym: POLÉBISZ) served as the country's aviation accident investigation agency for four years, when it investigated over five hundred aircraft accidents and incidents.