Ultramax Ammo Company fire Rapid City, S.D.
http://www.kotatv.com/content/news/Fire-breaks-out-at-Rapid-City-ammo-company-482080561.html (http://www.kotatv.com/content/news/Fire-breaks-out-at-Rapid-City-ammo-company-482080561.html)
https://www.ultramaxammunition.com/home.html (https://www.ultramaxammunition.com/home.html)
They are all probably required to do this, but Federal Ammunition in Anoka Minnesota has a bunch of small separated out buildings for storage