A large under-construction chimney at BALCO Power Plant in central India collapsed on Sep. 23, 2009 under severe stormy weather, causing serious casualties and massive economic losses, while another, similarly built, survived. So far, there has been no strict and scientific analysis on the cause of the accident. In this paper, finite element method is used to simulate the effect of wind loads and the whole collapse procedure based on the investigation of information about the design, the construction, the site related records, etc. The results show that the initial part of the chimney destroyed is the top of the structure (specifically the construction platform and the partial top cylinder wall of the chimney); then the debris from the top fells and crashes the lower part of the structure, eventually leading to the whole structure collapsing. The analysis results are basically consistent with the observation of the debris and the toppling scene and what the witnesses described, and scientifically clarify the actual cause of the chimney collapse. In addition, by comparing the chimney design codes between the USA and China, along with the analysis results, some suggestions are proposed to prevent similar accidents in chimney projects.