At 7.39 pm., the spark recognition system detected sparks in the pneumatic sorter of a woodchip panel manufacturing plant. The plant was shut down and extinguishing operations were started. Smouldering nests were also discovered in the fireproof wood chip silo ; the silo was consequently emptied via an emergency exit. At 01:14 am., 2 employees were sent to control the empty silo (without specific instructions). When they opened the door, a dust explosion occurred, injuring them severely. They both died on the following day. Material damage to the silo and sorter were evaluated at 5 000 euros. The emergency (fire) and working (entering a silo) procedures were audited and improved.