When I was in AIT, my battery XO had less time in service than any of the soldiers in my class (Firefinder RADAR repair). We were acting as OPFOR for another class' FTX and had set up an L shaped ambush along a ridge so they could practice react to direct fire. They kept getting distracted and the LT was getting impatient so he decided to pop an HC smoke behind us to "get their attention". Before I could tell him what a bad idea it was to use pyro in thick, dry grass, be had chucked out behind us. Right next to our ammo cans full of 5.56mm and 7.62mm blanks and grenade and arty simulators.