This article examines the conceptual framework for the social amplification of a risk issue with an analytic lens of System Dynamics. It will explore the dynamic interaction of general public, mass media, government agencies, and non-profit organizations; or what is called social stations, with regard to the national project of constructing the high-speed railway in Korea which was stopped by a Buddhist nunís 100-day hunger strike for protecting salamander and natural environment. Existing studies show that risk amplification occurs when media sensationalism causes risk perception and public concern to be magnified far beyond levels proportional to the risks estimated in risk assessment science. The case study underlines that social amplification is much accelerated within a highly networked society, or internet environment. Such process can create political over-activism or disruption, social conflict, or policy failure more costly than what the issue is.