It sounds to me like a microburst type event rather than a tornado - there were no reports that I've heard/read/seen of any funnel sighting. The TV pictures of the damage in Clonee (overturned cars, tiles off 100+ houses) a few miles to the west of the airport were quite alarming. I'm several miles to the south of the airport and can't even remember what the weather was like here that lunchtime so presumably unremarkable.
It has crossed my mind once or twice in the past that a 'proper' tornado could do a severe amount of damage in a busy major airport (I've seen pictures of what one can do to a GA field). Granted the chances of a twister touching down in any one given spot is very low, even in American states that are susceptible, but does the likes of Atlanta, for example have a plan for dealing with the arrival of a tornado with short notice? I guess it would be a case of evacuating all passengers from aircraft on stand to the terminal to ride things out, stopping arrivals and perhaps getting any taxi-ing departures into the air and the hell out of there?