You kid, but I live on the edge of Tornado Alley, and I've never even seen one. Been in the storms, seen the damage, had power knocked out for a week etc... but my point is, even here tornadoes are rare; in Chicago they're like bigfoot.
Their studio getting the fucking roof ripped off by one is noteworthy. And fucking hilarious! Can't believe it didn't destroy their sets, equipment, and props from just the water damage alone.
EDIT: I have seen many funnel clouds, and maybe I have seen one or two, but they were far off and difficult to tell as everything gets dark even in the middle of the day.