harold janes professor of mechanical engineering designed and built the tornado simulator called vorteksituation, to understand what happens to structures. >> tornado winds are rated on an ef scale which is an indicator of the severity of the storm based on wind speed and debris impact. >> this is ef 3e, 150 miles or less. >> have you ever been in this? >> oh, absolutely. would you like to go? >> this is what i've been waiting for. >> i'm going to build up the speed. >> so you're going to leave me here? >> you're good. >> at this point i was wondering just how powerful an ef3 would be. >> wow! >> now i can just about imagine how terrifying a tornado can be. >> to your research you're hoping to be able to recommend how to reinforce building codes. >> that's correct. what we really want to do is be able to recommend building codes and practices that people should consider when building in areas that are prone to tornadoes. we had no way of knowing how severe a tornado can be. we heard that it was on the ground. it looked like it was going to be a bad one. >> jimmy fleming, public informat