The most serious consequences have the so-called natural-technological disasters that have place when natural hazards trigger accidents and disasters at technological objects such as nuclear power plants, chemical plants, oil refineries and pipelines, or critical infrastructure facilities. In recent years, the number and severity of natural-technological events are increasing all over the world. One of the most large-scaled natural-technological disasters occurred on March 11, 2011 in Japan as a result of a massive earthquake and tsunami. A distinctive feature of natural-technological events is their synergistic nature with a disaster impact on the technosphere, resulting in simultaneous occurrences of numerous technospheric accidents. The consequences are the more severe the higher are the population density and concentration of industrial facilities and infrastructure in disaster-affected areas. The main goal of this open session is to summarize case studies of natural hazard impacts on technological systems and urban areas and to encourage a discussion about tools and methods to prevent or minimize their consequences.