Alert systems help avoid severe weather damage
Storms caused multiple outbreaks of severe weather most of Sunday from Kansas to Minnesota.
The National Weather Service's Storm Prediction Center in Norman, Okla., took the unusual step of warning people more than 24 hours in advance of a possible "high-end, life-threatening event."
In the end, only the Woodward tornado in Oklahoma proved fatal, killing five including three children. Residents and officials in hard-hit areas of Kansas, Iowa and elsewhere credited the urgent warnings with saving lives.