ST. PAUL, Minn. -- Residents of Sumner County, Kan., received a dire warning in April as a tornado barreled through toward Wichita: Get underground or into a shelter -- or else."Mass devastation is highly likely, making the area unrecognizable to survivors," the National Weather Service said.In an effort to get people to safety quickly, the weather service said Friday that it will expand its retooled severe-weather-warning system in Kansas, Missouri and 12 more Midwestern states.Starting Monday, it will provide media outlets and emergency services with more detail about the strength of a brewing tornado or thunderstorm, what it may hit and when. The system will also detail possible hazards and impacts of any potential tornado based on radar data, and more information on less severe but still "considerable" storms.Mike Hudson, a weather service meteorologist in Kansas City, Mo., said alerts with words such as "catastrophic" and "destruction" will likely be rare -- once a year in Kansas and twice a decade in northern states like Minnesota. The words will be reserved for "those types of tornadoes that ultimately take lives."The weather service started its expanded warning pilot in Kansas and Missouri last year after researchers found that Joplin, Mo., residents didn't get a strong enough warning about the May 2011 tornado.The Joplin tornado killed 161 people, injured hundreds more and destroyed thousands of homes and buildings.