The Turkey earthquake of August 17, 1999 offers an unprecedented opportunity to study the potential for strong earthquakes to precipitate environmental catastrophes. In this study, the authors report on their field investigations in Turkey in which they document and assess how this earthquake of magnitude 7.4, centered in the industrial region of Turkey, led to hazardous materials releases to the air, water, and soil. They report on several case studies of industrial accidents which occurred as a result of the earthquake, including the Tupras refinery fire, the release of toxic acrylonitrile from a chemical plant, and the intentional release of gaseous ammonia from a fertilizer plant. Also documented and discussed are the emergency efforts directed towards responding to these incidents. Copyright ASCE 2004.