>> up in his news chopper pilot welsh can see the storm approaching from the west. >> it's 2.5 miles from the university of oklahoma. and you know, you see a lot of people out on the streets. so my thought is these guys need to get covered and out of the way. >> captain david tysher is out in the city when the sudden appearance of a tornado takes us by surprise. >> we did have a little bit of a warning, but not a whole lot. >> when the storm first hits officers are told to return to the station. >> this is normally a rallying device incase communications go down. >> but the heavy rain makes returning to the station much more difficult. >> we could see the funnel cloud lowering, and we saw the power flashes, and then 30 seconds later the rain just kind of wrapped in around it and it was just like somebody just pulled the curtains and set them down. >> those are the ones that can be especially dangerous. because a lot of folks are in the rain. they're thinking maybe they're not going to be hit by the