Realism is thriving today in many types of media, particularly in video games, where the polygon count continues growing up. However, this realism pushes up the necessity of a real behavior of the virtual actors, in order to follow the credibility of the characters. We present an approach for crowd simulation that works adaptively to situations that occur in virtual atmosphere. Our approach allows that a realistic character adapts his behavior and actions with the information noticed from the atmosphere which it is close to. For this work, the execution atmosphere will be a simulation of a real catastrophic atmosphere, such as as flooding and collapses.