The 2012 Memorial Day explosion and fire at a Minnesota paper mill that killed an employee and injured several more was caused by an overheated air compressor that ignited oil vapors in the compressor and an air receiver. The report states the cooling water supply to the compressor was severely reduced in the hour before the explosion and that two other compressors had already shut off because of overheating. The report indicated that a maintenance issue or a mechanical failure possibly caused the one compressor to exceed its thermal protection shutdown controls. The MN State Fire Marshal lead investigator estimated the damage from the explosion and resulting fire at $50 million.
