PreparednessPreparing for an Explosive Attack

Explosives are a popular choice among terrorists for causing disruption, casualties and destruction. Although chemical, biological, radiological and nuclear (CBRN) weapons may cause much more damage, explosives can still be the first choice because they are relatively easy to make, transport and use. The Department of Homeland Security (DHS) Science and Technology Directorate (S&T) wants to make sure that state and local leaders have choices, too, by arming them with technology to plan for worst-case scenarios and mitigate the fallout of terrorist attacks.

“Explosives work and are effective weapons,” said Dr. David Reed, a chemist at S&T’s Chemical Security Analysis Center (CSAC). “The trade-off between difficulty to build and use versus the ability to cause harm is a decision that a terrorist probably considers. On the flip side, a decision-maker like a mayor might ask, ‘What are the most damaging scenarios that can occur and how can I protect against them?’ An analysis that considers the different buildings, explosive types, injuries and medical response can provide the information that begins to answer that question.”

With the very real possibility of explosive attacks in public spaces—like stadiums, special event routes, airports, places of worship, theaters, and others—the U.S. needs to be prepared by having security measures in place to stop them and effective medical response for attacks that do occur. With limited resources, knowing which security measures to use and which medical capabilities to emphasize are critical questions to answer before an attack happens.

S&T’s CSAC is developing a modeling tool called Homeland Explosive Consequence and Threat (HExCAT) that estimates the hazard and related human health consequences from thousands of plausible scenarios. HExCAT is currently focused on single event assessments of special events such as parades. After validation and further development, it will be integrated into national- and regional-level risk analysis.

“HExCAT is a holistic risk assessment that informs decision-makers like governors and mayors how to invest in security, plan for operations and mitigation, and make important decisions for securing public spaces,” said Reed, who works with CSAC’s Chemical Threat Characterization Team. “If a terrorist were to detonate a bomb in a building vs. a bomb during a marathon vs. a car bomb near a stadium, what physical security and medical countermeasures will be most effective?”