Annual probabilities of blast loads acting on building structures due to internal explosions are calculated by event and fault tree analyses. Influence factors in the internal explosions are identified from past accident experiences and used to create branched tree models by considering their causal relationships and correlations. Branching probabilities are determined from past accident data. A local database is built based on domestic public sources. The calculated values are found to be comparable to those of ISO 10252. Moreover, the paper provides the reassessment of past two accident examples from the point of view of accident probabilities.
