West Alton, Mo., June 6, 2013 -- Sandbags line levees through out St Charles county to protect homes, businesses and farm land. FEMA and the State of Missouri are doing joint Preliminary Damage Assessments (PDA) in the areas hit by a tornado. PDA is used to determine the magnitude and impact of an event's damage. The State uses the results of the PDA to determine if the situation is beyond the combined capabilities of the State and local resources and to verify the need for supplemental Federal assistance. Steve Zumwalt/FEMA