The Henryville Indiana tornado of March 2, 2012, rated an F4 on NOAA’s 0-5 Enhanced Fujita scale. This tornado caused massive destruction and was on the ground for more than 50 miles, and generated winds to 170-mph.
This is footage from one of the Henryville High School surveillance cameras. This video shows just how fast and powerful a tornado can be. It took less than 3 seconds (literally 3 seconds!) to destroy this gymnasium. Had there been anyone in the gym at the time, it's unlikely there would have been any survivors.
Take tornado warnings seriously. You might think you can see one coming, and you might think you can get out of the way, but you can't. This video is the perfect example.