To understand the accident and at the same time to create a proper emergency scenarios, it is necessary to know the physical nature of emergency events. The aim of this contribution is to describe the possibility of verifying the characteristics of the phenomenon of Fire Ball, as accidental phenomenon, which is often present in major accidents in the industry. At the beginning of the contribution are described the conditions that are necessary or sufficient for its creation. There is also described a simple model for calculating the basic parameters related to this phenomenon - size, diameter, duration, effects distance, etc. In the second part of the contribution three major fire ball accidents using the ARIA and e-MARS databases are described. In the third part of the article description is made of the currently used mathematical models of the phenomenon and a comparison is made of the mathematical model developed and used for this work with the results of experimental simulations, theoretical models and the data from the accident with the occurrence of this phenomenon.