On September 26, 2019, a large-scale fire affected the Lubrizol industrial site in Rouen, France. Despite the effectiveness of the emergency response in bringing the blaze under control, the accident gave rise to numerous critical reactions from the public, widely reported in the media. This event is an opportunity to question the consideration of public concerns as a risk management criterion. Reading the collection of various declarations and positions is particularly complex and leaves an impression of unintelligibility. In the context of this accident, this paper presents the interest of setting up a specific reading grid resulting from a methodological framework proposed by Ortwin Renn, to allow an organization of speeches restoring the bases of intelligibility necessary for a work of analysis and comprehension. This reading grid has three levels, and our comprehensive case study tends to validate the hypothesis that links incomprehension and tensions between the stakeholders with a shift in the levels of discourse between the interlocutors.