Please Provide the diagram also

An Accident occurred somewhere and the security officials were trying to conduct an investigation of the accident. They initially collected the evidence and after making analysis and integrating the facts some conclusions were drawn. Some recommendations were aligned after validation. However in order to collect the evidence the official need to visit the site and the evidence after identification must be preserved. Along with the evidence witness collection and interviewing those witnesses is very important. And the integrated information is reviewed. Moreover, interviewing a witness needs a proper place. The officials can provide a meeting room and let the witness explain the incident details. Officials must ask some open ended questions that must ensure 5Ws (What, Where, Who, When, Why) and 1H (How)