OSes: /.: NERC Releases Interim Report on Aug 14th Blackout. ‘part of the blame for the big fizzle of 2003 lies with a failing SCADA system, GE’s XA/21 power management system. ‘Not only did the software that controls audible and visual alarms stop working at 2:14 p.m. EDT, but about a half hour later, two servers supporting the emergency system failed, too.’ According to the product specs, it is a Unix system with X Windows.”
However, further reading through the comments throws up this gem, which notes that the ‘software that controls audible and visual alarms’ and the ‘two servers’ noted above were all Windows systems. The comment author ties this to Blaster worm activity causing DDOSes on the monitoring networks.