Chicago Tornado Risk Analysis and Planning Considerations
Prepare, Respond, and Recover: Engineers' Involvement with Local Disasters
October 19, 2006
Chicago All-Hazard Risk Approach
n Consistent with the State’ Approach s n However, still unique to Chicago’ environment s n Sliding Scale System n Based on: n Probability of the Event Occurring
n
Direct and Indirect Impacts
Identify Hazards
“ can happen to Chicago” It
Natural SENSITIVE INFORMATION
Political • Terrorism • Biological • Chemical • Nuclear/Radiological • Munitions (Bombing) • Cyber • Riot • Civil Disturbances • TORNADO • Flood Technological • Hazardous Waters • Hazardous Materials Release / Coastal Storm •Fixed Facility • Severe • Transportation Storm/Lightning • Fixed Facility • Wind • Large Scale Fire • Winter Weather • Structural Failure • Earthquake • Critical Infrastructure Incident • Fog • Transportation Systems • Extreme Temp • Utility Failure • Drought • Space Weather • Disease, Epidemic
A Few of the Big Ones…
Chicago n March 4, 1961: An estimated F2 tornado hit the south side, causing 25 million in damages,
115 injuries and 1 fatality. The tornado path was between 91st and Western to 68th and Lake Michigan.
n April 21, 1967: F4 tornadoes struck Belvidere, Lake Zurich, and Oak Lawn during rush hour
leaving 58 dead, 1,100 injured, and $100 million in damages. The tornado skipped across the south side of Chicago, crossing the Dan Ryan Expressway at rush hour.
n August 25, 1972: A F2 tornado caused about $2.5 million in damages for a 2-mile stretch
that was 200 yards wide, passing closely to O’ Hare Airport.
Regional
n June 13, 1976: A F4 tornado, Lemont. n August 28, 1990: A F5 tornado, Plainfield n March 27, 1991: F3 tornado, Lemont. n April 20, 2004: F3 tornado, Utica, Illinois
Chicago Tornado History
Probability Analysis
Tornado Hazard Probability
ü42 documented tornadoes within the Cook County area since 1955 • seven have crossed into City of Chicago municipalities. ü1 tornado within Cook County in the last 10 yrs ü 75% of past tornadoes have been F1 to F2 • Only slightly above average in relation to Illinois and FEMA Region V
Tornado Hazard Impact Analysis
üExtensive damage from small tornado. Factors: •Built environment •Condensed populations ü Past Chicago-area tornadoes, have tallied $150M ü Damage to critical facilities, systems, infrastructure ü Casualties/injuries will be dependent on time and location •Worse case scenario being “ rush-hour” . ü Debris operations will impede city functions, operations, and commutes. ü Housing & Sheltering
Chicago’ Tornado Risk s
Relative to other Hazards…
ü In past 55 years, 7 have hit Chicago •Consistent with # of tornados per sq. mile üThe ratio of tornado intensities consistent with county, state, and FEMA Region V üDense development = significant damage •Even from a small tornado
Tornado Modeling
ü 13,000 buildings
damaged, totaling $4B ü Apx. 78,000 people directly affected ü Facilities affected include:
• • •
1 medical care facility, 2 fire stations, and 19 schools
1967 Tornado Through Central Business District
Demographic Impacts
Building Impacts
Critical Infrastructure Impact
Critical Infrastructure Impact
How Can Engineers Get Involved???
n Create relationship before the event n Multi-agency Coordination System n ChicagoFIRST n BOMA n Illinois Terrorism Task Force n Building Industry Emergency Response Network n Obtain disaster training
Questions & Answers
Daniel Martin, CEM, CFM 847.477.6542 Dwmartin75@aol.com John Rogan 773.383.7221 jrogan@cityofchicago.org