Over the years, the world has witnessed fires in enclosed environments. These fires have caused direct and indirect losses. These events are more critical in terms of human fatalities. This book discusses the first aim of fire safety -- to provide the safety of occupants, and to avoid and/or reduce the number of fatalities (and/or the number of injuries). A broad overview of the current state-of-the-art of fires in atria are also discussed. The international tendencies towards the introduction of performance-based fire protection codes are addressed and the overview examines the numerous scientific advances achieved and also highlights the need for further experimental studies and validations of numerical simulations for a wider range of fire conditions in atria. A brief review on the updated use of computational fluid dynamics (CFD) in building fire studies is also explored, in addition to the development of specific strategies for the protection of process equipment from catastrophic failure caused by external fires.