Karenlynch
There was certainly plenty of advanced warning from the NWS. I don't know what kind of advanced notice the airport itself passed along to staff and patrons, but the first NWS warning issued for the area around 7:30 PM included the airport itself: http://mesonet.agron.iastate.edu/vtec/#2011-O-NEW-KLSX-TO-W-0046
A new warning, issued at 755 PM, included the airport and areas to the ENE towards the river: http://mesonet.agron.iastate.edu/vtec/#2011-O-NEW-KLSX-TO-W-0049
This second (later) warning was 20 minutes prior to the airport tower reporting a tornado on the ground at 814 PM.
I stand corrected, I have no idea how I missed that! If there was a confirmed tornado on the ground headed their way 20 min prior, then why the heck didn't they do something???