Fire broke out in the nitrocellulose warehouse at a printing ink plant closed for its annual holiday period. Given the absence of onsite personnel and fire detection systems inside the warehouse, notification was given by the plant’s neighbours. Fire-fighters arrived quickly at the scene and had the incident under control within 30 min. The premises were destroyed: 3 walls collapsed, only the facade fitted with a metal access door was able to resist the fire. The 4 tonnes of nitrocellulose (including 3.6 tonnes delivered just a week earlier) stored in the depot were destroyed, along with the 6 barrels of substances already in use (accounting for approx. 100 kg), laid out in 2 cores abutting the warehouse. According to the site operator, the products already in use had been adequately packaged in their original plastic containers placed in hermetically sealed barrels. Given the intense heat recorded during the days leading up to the accident along with the absence of personnel over the preceding 5-plus day period, the evaporation of nitrocellulose impregnation solvent would have caused its self-ignition. A decree issued by the Prefecture had mandated constant supervision of the storage zones in order to ensure that the level of solvent concentration did not drop below the normal content recorded at the time of material acceptance. The Classified Facilities Inspectorate made note of these conditions. A Prefecture order of emergency measures was enacted: the operator was required to maintain the vulnerable installation in secure mode and properly dispose of waste using a specialised facility. Service restart at the site was made contingent upon receipt of a new permit. Prior to awarding such authorisation, the causes and consequences of this accident had to be determined by implementing all of the measures intended to reduce the probability of a repeat occurrence. In order to bring the production process back online without delay, the operator agreed to organise supply deliveries every morning with just the strict minimum quantity of nitrocellulose required to cover the day’s production output.