Russell Lewis

For many, the only way they learn a tornado is approaching are sirens. In the spring and summer, tornado sirens go off a lot more when twisters roar across Alabama, which has been hit by 900 since 2000, accounting for a quarter of all U.S. tornado deaths.

"I am still surprised that so many people rely on just one source of getting warned, and that has to change," said Jim Stefkovich, meteorologist in charge of the Birmingham office of the National Weather Service.