Holowan Massacre

The Holowan Disaster took place in 11 BBY on the planet Holowan. Once the assassain droid, IG-88, was activated, he killed his creators, programmed and activated his counterparts, and together with IG-72, they went through the facility killing all the personel. Once all of the personel they could detect were dead, they escaped the planet, and headed for Mechis III.