The New Madrid fault crosses 5 states lines and crosses the Mississippi River 3 times and the Ohio River twice. It is currently an active fault that affects Tennessee, Illinois, Kentucky, Arkansas and Missouri. Alot of people don’t think of it as being dangerous because it was little known for a while. Plus, most of the earthquakes you hear about in the U.S. occur on the west coast. That being said, this makes the New Madrid fault more dangerous because most people in that area are highly unprepared for such an earthquake.