joplin, missouri, the biggest hospital for miles around. >> st. johns is a 230-bed acute care hospital. >> reporter: jim risko has been an e.r. doctor at st. johns for the last 17 years. >> this is a very, very sophisticated hospital in a relatively small townme. >> i was down the road playing horseshoes. >> reporter: andrew mcdaniel came to the hospital to visit his grandmother on may 27. as he arrived, a sound familiar to every mid westerner. >> the sirens started going off. i looked and didn't see much other than dark clouds over there. i didn't think anything of it. >> reporter: but in those dark clouds, a monster tornado was headed right for them. at st. johns it was the moment they trained for that they hoped would never come. >> we drill -- well, actually just by virtue of the fact that we're in tornado alley down here, we prepare several times a