The tornado that struck Joplin, Missouri last year killed 161 people, injured nearly one-thousand and destroyed a quarter of the city.
A nurse who helped care for the injured says frequent drills and revisions to response plans saved lives.
Marilyn Welling works at St. John's Hospital. She said the city was preparing for a disaster drill when the tornado struck in May.
She said, “If you do drill and you have your command center, you have a plan in place that tries to be as comprehensive as possible, you can prepare. It will make a difference.”