An explosion today in Winterset claimed the life of a volunteer firefighter and a civilian. Winterset Assistant Police Chief Terry Miller says firefighters were called to a fire near a gas tank at 10:56 this morning. The tank exploded, killing two people and injuring eight other firefighters and a civilian. Miller says workers had been cutting at the base of the tank when a grass fire started. Firefighters were trying to put out the grass fire when the explosion occurred.