The purpose of this paper is to promote a complementary myth to "compliance to rules ensures safety" namely that "operational managers build safety by creating favourable environmental conditions for safety work". By a "myth" we understand a story that expresses a partial truth about a phenomenon. "Environmental conditions for safety work" refers to conditions that influence the opportunities an organization, organizational unit, group, or individual have to control the risk of major accidents and work environment risk. Based on a literature review and qualitative interviews we elaborate on the idea that operational managers build safety by creating favourable environmental conditions by discussing two examples from the petroleum industry: 1) How a failure to create favourable conditions for safety work contributed to the explosion at BP's Texas City refinery in 2005. 2) How operational managers in the Norwegian petroleum industry actively try to prevent excessive stress and time pressure related to downtime in drilling operations. We conclude that a failure of senior management to provide adequate environmental conditions for the safety work of operational managers may indirectly contribute to accidents. Operative managers can build safety by creating favourable environmental conditions for safety work for workers at the sharp end. Safety is not ensured by a single means, such as compliance to rules, and creation of favourable environmental conditions for safety work is therefore an essential part of a more complex account of safety.