Wired is doing a really good job of covering this truly shocking incident. Apparently a week ago a group of robotic cannons — capable of acquiring targets and reloading themselves — was being tested in a line on a firing range in South Africa. One unit unexpectedly swiveled too far to the left and opened up on the rest of the line. With one 1/8 second burst it killed nine soldiers and wounded 15.
The Mail & Guardian, a South African paper (I think), has more.