The Louisiana National Guard has identified the substance that exploded Monday at Camp Minden.  According to a statement released Friday, the substance that exploded was a smokeless powder that does not pose a threat outside of Camp Minden.  The force of the blast from the underground bunker shook homes and businesses in Webster Parish and rattled nerves when it happened around 11:30 p.m. Monday. Early Tuesday morning, crews from Explo Inc., discovered that one of their storage areas had exploded and reported the incident to the Louisiana National Guard. Following this report, the Louisiana National Guard notified local authorities and the Louisiana State Police of the explosion in accordance with standard protocol.  The incident is under investigation by the State Police.  It could take weeks before a determination is made as to what caused the blast.