Among the available methods for the analysis of accidents/injuries, the AEB approach (Accident Evolution and Barrier Analysis) and the 3CA-Form B method (Control Change Cause Analysis) have been used to analyze a typical accident, which often occurs, in which have been involved several workers that entered in a confined space containing toxic and/or inert gases, causing the workers death. A critical analysis of the investigated methods has been performed in order to identify the best available methodology; in particular, it was evidenced a problem of events representation with the AEB method because the large part of the causes was due to human factors, so the entire sequence of the events that led up to the accident is represented in a linear way, on a same column, by this approach making difficult to relate events that took place simultaneously. The 3CA-Form B method allows, on the other hand, a good description of the events sequence taking into account simultaneously all aspects and issues, both human and technical, that characterize it
