According to the Ars Technica article http://arstechnica.com/business/2016/08/data-center-disaster-disrupts-delta-airlines/ http://arstechnica.com/business/2016

According to the Ars Technica article http://arstechnica.com/business/2016/08/data-center-disaster-disrupts-delta-airlines/ http://arstechnica.com/business/2016/08/data-center-disaster... a fire broke out in their main datacenter. Assuming that was true, employees were most likely evacuated and at the very least would have been distracted. Their disaster recovery plan may have assumed that there would be admins onsite to run a manual switch, may have assumed a complete failure instead of a partial failure or may have had per application disaster recovery plans. Disaster recovery is a difficult and stressful process in normal times, much more so when your regular workstation(s) are unavailable and you're faced with a disaster-level distraction like a fire.