The 2000s began with a computer "time bomb" scare (Y2K) which ushered in a whole new set of threats that had almost been non-existent before. Viruses, worms and other computer, internet or e-mail net problems began to proliferate. Other threats began to appear which were previously dormant, for example, many dams were built on karst topology and began to show signs of erosion causing fears of failure, new viruses began to appear that challenged health personnel (West Nile, H5N1 avian flu and H1N1 swine flu), and the climate of the globe began to apparently warm up which caused significant weather trouble, including more thunderstorms and tornadoes, hurricanes and typhoons, flooding and droughts, ice storms, forest fires and wildfires and other extremes in weather temperature. For the first time, dikes holding back piles of coal ash failed causing hazards for homes near the break and potential environmental dangers. Other threats appeared due to the growth of programs that were previously much smaller, such as accidents from increased activity at the entire Oak Ridge reservation and an increase of transportation of environmental wastes from K-25, X-10 and Y-12. New issues arose requiring emergency management involvement in the near emergency conditions that occur in fuel and water shortages, in potential epidemics or pandemics and developing weather that could potentially produce a hurricane and cause evacuations.
During the 2000s Tennessee was the host of evacuees from Louisiana after Hurricanes Katrina and Rita and Hurricanes Gustav and Ike. Approximately 3000 people were housed in official shelters in both emergencies. Tornadoes and floods have continued to occur with increasing regularity along with an increase in hazardous materials incidents.