An explosion occurred when 6 personnel were working on the repair of a catalyst tower Proximate causes: • Lack of work rules/policies/ standards/procedures (wrong procedures for inspections); • Inadequate work rules plan (lack of the pre-start safety review before inspection). Source: A web-based collection and analysis of process safety incidents (https://www.sciencedirect.com/science/article/abs/pii/S0950423016302285)