you might know simon brewer from the weather channel series "storm riders," he's actively chasing these us on the phone. let's start with chris. this one turns out to be one of the big ones. ef-5. tell me how that differs from -- when you get up to 200 miles an hour, what that's capable of doing to property, human, animal, life, whatever, buildings. >> just as you can see, it's just utter destruction everywhere you look. there are houses completely ripped off their foundations. it's an awful scene here, as you can plainly see. when you get up into the ef-5 range, that's incredible damage. that's how they categorize that. and it's just awful, as is obvious on the ground here in moore. >> we're looking at kind of a snaking, it's a little bit wider than a snaking twister. it's one of those that sort of to me is iconic. an iconic twister. how close can you get to watching that when you take people to go look at it and hopefully are safe when they do it? >> well, we do everything safely, my storm tour company. a tornado that large, we would not get very close to with a tour company -- with,