On a Sunday, following the untimely activation of a fire alarm, as relayed by a video surveillance warning, fire-fighters attended a chemicals warehouse without initiating the company’s on-call chain of command. Thermal camera-based controls confirmed the absence of fire. An employee based in the Ile-et-Vilaine jurisdiction, contacted by the local fire department, managed the incident and was able to inform a company employee who, not being on-call, arrived 30 min later, while on-call personnel remained unavailable. The warehouse operator ran reliability tests on his fire detection system, which had already experienced several malfunctions, and updated his on-call protocol: updated phone numbers, imposed response times, etc.