Why are some vegetation fires allowed to burn? - A fire burns at Ranges 108 and 109 on Marine Corps Base Camp Pendleton, California, June 12, 2019. The Camp Pendleton Fire Department encounters several wildfires each year, some of which they will let burn in order to prevent larger fires in the future. The firefighters will also avoid fighting a fire if there's a potential for unexploded ordnance to be in the area, and will instead monitor the blaze until it goes out. (U.S. Marine Corps photo by Lance Cpl. Drake Nickels)