They breached the minimum safe distance
MSD, used for peacetime training missions, is the prescribed minimum safe distance
in meters from the intended center of impact at which a specific degree of risk and vulnerability will not be exceeded with a 99 percent assurance.
For example, aircraft delivering munitions must stay outside the minimum safe distance
of artillery shells detonating on nearby targets and stay 1000 feet from the trajectories of those and other weapons.
As a back-up, the platoon leader and forward observer (FO) of the lead platoon entered the targets as "waypoints" into their precision lightweight global positioning system receivers (PLGRs), allowing them to calculate the precise minimum safe distance
and adjust the guns to the next target as the lead elements of the company moved within that distance.