I'm not sure if this deserves its own thread and its not exactly naval per say. I stumbled across it on Wikipedia, double checked it and it is true and as such is hilarious and slightly scary.
"12 October 2007: Nine South African National Defence Force (SANDF) soldiers were killed and 14 injured by the system during a training exercise at the SANDF Battle School at Lohatla in the Northen Cape province. A line of 8 cannons were engaging a tank hulk in manual ground fire with the guns at low elevation and the maximum traverse of the barrels secured by safety poles and tethers. The rightmost gun jammed while firing and had to be repaired by technicians. Shortly after the gun was cleared to fire again, the gun malfunctioned, entered automatic mode, broke through the traversal-restriction safety mechanisms and began firing, striking the other guns along the firing line. Initial reports suggested that the malfunction was caused when the gun underwent an unexplained gang fire of the explosive 35mm ammunition in the magazines, causing the turret to swing uncontrolled through 360-degrees firing wildly until it exhausted its remaining ammo. A statement issued by the South African Defense Minister Mosiuoa Lekota, however, stated that the gun had inexplicably traversed 90-degrees to the left, breaking through the safety mechanisms, and fired only a 1/8 second long burst, striking all of the soldiers located on the right hand side of their guns. The accident report published by the SANDF in January 2008 blamed "undetected mechanical failure—which the manufacturers of an anti-aircraft gun allegedly kept secret". The report says the gun malfunctioned because a spring pin, which is the size of a matchstick, sheared. Other sources blamed poor training and safety procedures in the SANDF."
http://www.wired.com/dangerroom/2007/10/robot-cannon-ki/
http://www.iol.co.za/news/south-africa/army-blames-gun-s-maker-for-lohatla-1.387027#prof
http://en.wikipedia.org/wiki/Oerlikon_35_mm_twin_cannon
"12 October 2007: Nine South African National Defence Force (SANDF) soldiers were killed and 14 injured by the system during a training exercise at the SANDF Battle School at Lohatla in the Northen Cape province. A line of 8 cannons were engaging a tank hulk in manual ground fire with the guns at low elevation and the maximum traverse of the barrels secured by safety poles and tethers. The rightmost gun jammed while firing and had to be repaired by technicians. Shortly after the gun was cleared to fire again, the gun malfunctioned, entered automatic mode, broke through the traversal-restriction safety mechanisms and began firing, striking the other guns along the firing line. Initial reports suggested that the malfunction was caused when the gun underwent an unexplained gang fire of the explosive 35mm ammunition in the magazines, causing the turret to swing uncontrolled through 360-degrees firing wildly until it exhausted its remaining ammo. A statement issued by the South African Defense Minister Mosiuoa Lekota, however, stated that the gun had inexplicably traversed 90-degrees to the left, breaking through the safety mechanisms, and fired only a 1/8 second long burst, striking all of the soldiers located on the right hand side of their guns. The accident report published by the SANDF in January 2008 blamed "undetected mechanical failure—which the manufacturers of an anti-aircraft gun allegedly kept secret". The report says the gun malfunctioned because a spring pin, which is the size of a matchstick, sheared. Other sources blamed poor training and safety procedures in the SANDF."
http://www.wired.com/dangerroom/2007/10/robot-cannon-ki/
http://www.iol.co.za/news/south-africa/army-blames-gun-s-maker-for-lohatla-1.387027#prof
http://en.wikipedia.org/wiki/Oerlikon_35_mm_twin_cannon