THREAT AND HAZARD IDENTIFICATION AND RISK ASSESSMENT (THIRA)


Threats and Hazards of Concern

NATURAL HAZARDS

  • Drought/Extreme Heat

  • Earthquake

  • Epidemic

  • Flood

  • Landslides, Land Subsidence, Sinkhole

  • Severe Thunderstorm (Hail, High Winds, Lightning)

  • Tornado

  • Wildfire

  • Winter Storm (Snow, Ice, Extreme Cold)

TECHNOLOGICAL HAZARDS

  • Dam Failure

  • Hazardous Materials Accident (Fixed Facility/Transportation)

  • Nuclear Power Plant Accident

HUMAN-CAUSED HAZARDS

  • Terrorist Acts

 

Threats and Hazard Scenarios

NATURAL HAZARDS

THREAT/HAZARD

    POSSIBLE SCENARIOS

Drought

Extreme Heat

  1. Drought conditions cause crop failure.

  2. Drought conditions cause problems with water supplies.

  3. Extremely high temperatures cause injuries and death of residents without air conditioning.

Earthquake

  1. An earthquake weakens the structural integrity of bridges and buildings.

  2. Weakened bridges delay response time in emergency situations.

  3. An earthquake affecting other counties will bring refugees to Limestone County.

Epidemic

  1. An outbreak of TB has occurred at a local elementary school causing numerous children to become ill.

  2. A 17 year old boy has been diagnosed with bacterial meningitis.

  3. A local nursing home has reported several cases of influenza.

Flood

  1. Flash flooding causes numerous traffic accidents.

  2. Flooding in low elevations has caused residents to become stranded as the water continues to rise.

  3. Flooding has caused delayed response by emergency responders to assist residents in evacuating their homes and assisting those involved in traffic accidents.

Landslide

Land Subsidence Sinkhole

  1. A Landslide causes damage to houses and injures occupants.

  2. Land Subsidence occurs under a resident causing injury to occupant and damage to the home.

  3. A Sinkhole occurs under a major highway injuring motorist and causing traffic jams.

Severe Thunderstorm Hail

High Winds

Lightning

  1. Hail causes minor damage to homes.

  2. High winds occur during the Tennessee Valley Fiddler’s Convention, causing tents, chairs and other equipment to hit and injure attendees.

  3. Lightning strikes cause a wildfire and a structure fire to a home.

 

Tornado

  1. A Tornado strikes a school killing and injuring students

  2. A Tornado strikes downtown Athens killing and injuring many.

  3. An EF-5 Tornado travels across the entire county causing numerous injuries and deaths and destroying hundreds of homes.

Wildfire

  1. A Wildfire starts near a residential area and destroys homes and businesses.

  2. A Wildfire causes injury or death of firefighters.

  3. A Wildfire travels though a nature preserve killing numerous animals.

Winter Storm

Snow

Ice

Extreme Cold

  1. Ice accumulation on power lines causes power outage to critical care facilities.

  2. Ice accumulation on roadways has made travel extremely hazardous for residents and emergency response personnel.

  3. Extremely cold temperatures cause injuries and death of residents with inadequate shelter and for the homeless.

  

TECHNOLOGICAL

THREAT/HAZARD

    POSSIBLE SCENARIOS

 

Dam Failure

  1. Dam Failure occurs causing flooding and contaminating potable water source.

  2. Dam Failure occurs destroying homes and businesses.

  3. Dam Failure occurs causing flooding which results in numerous deaths of residents and animals.

 

Hazardous Materials

Fixed Facility

Transportation

  1. A hazardous chemical release occurs on a windy day upwind from an outdoor event causing injuries.

  2. Chemical spill near a waterway contaminates water and exposes wildlife.

  3. A train carrying hazardous chemicals derails in downtown Athens.

 

Nuclear Plant Accident

  1. Accident at Browns Ferry Nuclear Plant poses a health threat to onsite personnel.

  2. Accident at Browns Ferry causes spontaneous evacuations resulting in traffic jams and wrecks.

  3. Release of radiation from Brown Ferry results in residents living near the plant being exposed to radiation.

 

HUMAN-CAUSED

 

THREAT/HAZARD

    POSSIBLE SCENARIOS

 

Act of Terrorism

  1. A biological agent was released into the air conditioning system of a critical facility resulting in many workers becoming severely ill and in several deaths.

  2. An explosive device was set off at a public event causing death and injury to citizens.

  3. Hostage situation occurs at a school.

  4. Computer virus or hacking results in the loss of important documents, government, military or industrial secrets.