South Dakota's fire marshal says an explosion near Britton that killed two volunteer firefighters and injured a third was caused by spontaneous combustion in coal.
Twenty-two-year-old William Waldner and 20-year-old Jacob Waldner died September 15 while battling a coal bin fire at the Sunset Hutterite Colony. Jacob Waldner's father, Jack, was injured. The firefighters were on top of a building when the explosion blew off the roof and a wall.
Fire Marshal Al Christie says there was nothing the firefighters could have done to prevent the blast.