Downers Grove changes tornado siren policy after EF-1 tornado hit town with no siren activated

triblocal.com/downers-grove NWS Tornado Warning was a rare blanket warning covering a wide area that didn't prompt officials to activate siren ...

crh.noaa.gov National Weather Service Chicago maps of June 21st Suburban Chicago Tornadoes that hit Downers Grove and Mount Prospect  ... 

arlingtoncardinal.com/2011/06/21/The NWS Tornado Warning that was issued at 7:57 PM CDT Tuesday, June 21, 2011 that covered a wide area including Downers Grove and all of DuPage County  ...