Rapid City Fire Department provided an update on the situation about an hour after the fire was reported. Public Information Officer Jim Bussell says there are millions of round of ammunition in the building. As a precaution, they are moving firefighters away from the fire and setting up a 2,000 foot perimeter.
Bussell says a number of roads are closed in the area to keep the public away from the dangerous situation.
This is a developing story.