FILE - In this Aug. 14, 2011 file photo, Indiana State Police and authorities survey the collapsed rigging and Sugarland stage on the infield at the Indiana State Fair in Indianapolis. The stage collapse before a Sugarland concert was a late wake-up call for people who manage large public venues like concert grounds and football stadiums. Venue managers gathered in Norman, Okla., Tuesday and Wednesday, March 5-6, with weather forecasters and revealed there have been many close calls. (AP Photo/Darron Cummings, File)NORMAN, Okla. (AP) — Experience organizers have learned the onerous method that the same old half-hour warning of extreme weather could be sufficient for people in their houses, but it's now not enough to clear folks from big venues the place concert events and soccer games are held.