WSN is frequently used technology in the world. The wireless sensor network contains number of sensor nodes which has most power to sense the data and transmit it to the administrator in effective way. Disaster management is one of the important aspects of wireless sensor network. Disaster alarm system can be helpful to save lives in great extent. Till now, variety of techniques for event detection has been put forward, but fuzzy mechanism is used in those techniques. Fuzzy logic did not show clear output.