Abstract: To reveal the causation of a gas explosion accident in America, the causes of unsafe acts, habits and organizational behavior are analyzed based on the behavior safety 2-4 model. We find that there are six major unsafe acts and habitual behaviors and the organizational behavior causes are four defects in safety management system. Based on our study, improving and implementing the safety management system, strengthening targeted safety training and modifying the unsafe acts of employees are proposed as preventive measures.