A paper mill explosion in Sartell, Minnesota left one worker dead and five others injured Monday afternoon. The explosion and subsequent fire was caused by a malfunction in an air compressor, the Duluth News Tribune reports.

Fifty employees were at the mill when the explosion occurred. The deceased’s cause of death and the conditions of those injured were not released. One firefighter suffered heat exhaustion and was treated at the scene.

Officials do not believe any hazardous material escaped, though it warned nearby residents downwind of the mill to stay inside due to the smoke. Most of the fire was under control by that evening.