A deflagration occurred on a cyclone filter inside a sawmill/wood shop. Sawdust, chips and incandescent filter sleeves were spewed by the blast wave onto neighbouring roofs. The fire engulfed 500 m² of a production building roof and 300 m² of roof on a maintenance building. After evacuating shop personnel, 40 fire-fighters controlled the blaze by deploying 3 hoses. A new outbreak detected in the silo 2 hours later was extinguished also using a hose. One person sustained skin burns on the shoulders. No employees were made redundant.