The purpose of this research is to study the actions of on-site commanders in suicide cases, in which Liquefied Petroleum Gas (LPG)/Natural Gas (NG) is used as a suicide medium. With increasing LPG/NG suicide cases, the ways taken by the suicides tend to be diverse and violent. For example, that suicide attempts trying to ignite LPG/NG or gasoline not only catches close attention from the public, but also threatens firefighters and the mass population. Furthermore, although some other types of suicide, such as suicide jumping, wrist cutting, drugs taking, hanging, and burning charcoal, won’t result in much life threat to firefighters, they still create quite a lot economical loss in families, and societies on medical treatment, education, economics, and mental health. National Fire Agency, Ministry of Interior, Taiwan, has established a Standard Operation Procedure (SOP) for Fire Fighters Dealing with LPG/NG Suicide Cases in March 2005. However, on-site commanders still used to respond to LPG/NG Suicide incidents on their own immediate instinct. This can’t help solve problems efficiently. Besides, it possibly causes unnecessary injuries and death due to impropriate operation. As a result, city/county fire departments remain to be improved on rescuing actions. This research collects and generalizes the theories of crisis management, and the proper crisis management actions should be taken by on-site commander for such suicide incidents. In this thesis, a real NG suicide case happening in Keelung dealt by Keelung Fire Department is studies based on the interview of firefighters involved for the discrepancy between theory and practice. Hopefully, the presentation of substantial conclusions and recommendations may contribute to the safeties of firemen in handling such cases in the future.