At 2 pm, personnel at a coffin factory noticed the presence of incandescent elements on the upper part of the 250 m³ silo of sawdust supplying a 4.5-MW boiler. First responders sprinkled the 50% full silo and emptied it down to 15%. Installations were restarted the next morning; less than 30 min later, the silo exploded in three distinct blasts, causing significant deformation of its containment vessel and bending its alignment against a supporting building.

The sawdust collection and feeding machinery was destroyed. Flames from the ensuing fire spread to a maintenance building and melted all plastic components within a 20-m radius. The response of 25 fire-fighters prevented the accident from engulfing the entire site by sprinkling adjacent buildings. The company (170 employees) had to shut down for 48 hours.

Residual incandescent or hot elements might have remained after the silo was partially emptied subsequent to the first incident. The silo had become unstable and had to be demolished. It had not been equipped with venting pipes, which was at odds with conditions listed in the initial authorisation application. The rupture of piping or filtration components could have led to their projection. Inspection Authorities for Classified Facilities recorded the facts and proposed a Prefectural injunction for the factory operator to equip all site installations exhibiting dust explosion risks with the necessary protection devices.