Three key ingredients are needed for tornadogenesis: 1) a persistent, rotating updraft, 2) ingestion of enhanced storm relative helicity and development of strong low-level rotation, and 3) a downdraft that transports rotation to the ground. Analysis of radar data from multiple tornadoes in Illinois in 2009 showed strong low-level rotation signatures and tornado damage assessments ranged from EF0 to EF3. Guidelines are suggested for activating tornado sirens to avoid unnecessary public alerts.