This document discusses the role of emergency physicians in responding to CBRNE (chemical, biological, radiological, nuclear, and explosive) attacks. It begins by defining key terms like disaster, mass casualty incidents, and terrorism. It then reviews lessons learned from past terrorist attacks involving weapons of mass destruction. Early detection of biological attacks can be aided by syndromic surveillance of emergency department visits. The document outlines recommended preparedness criteria for emergency departments. Finally, it describes the "seven Ds" that define an emergency physician's role in disaster response: detection, declaration, defense, decontamination, delegation, drugs, and disposition.