On December 21, 1997, three volunteer firefighters from Iredell County, North Carolina were injured in an explosion in a silo used to collect and store wood waste for utilization as fuel at a cord reel manufacturing facility. The silo was an agricultural type that had been converted for use as a collector for sawdust. The structure had been the site of a minor explosion five years previously that had caused no injury. The firefighters had been directing water into the silo for over two hours from openings in the silo roof when the decision was made to access the wood product inside. A loud, low order explosion destroyed the top of the silo and endangered the firefighters who had been operating on the roof. The explosion buffeted personnel operating on the ground as well.