Southwest Airlines experienced issues with "multiple technology systems" today. It left flights grounded and the website inoperable.
It's amazing that their business can grind to a halt because their IT systems failed. Does anyone have details on what exactly failed?
It sounds like it included a ticketing/reservation system (may have been more, but most of the problems reported except the main website -- well, unless some poorly-designed tight coupling was in place -- seem to be explainable by that.) If you can't validate printed tickets, generate boarding passes, know who has a ticket (or how many people have tickets) for a flight, etc., your business -- as an airline -- is kind of in a bad place.