In the field of risk and disaster, a great deal of research has been carried out into the concepts and analysis of major disasters. On the basis of this work, we have constructed a formalized ontology of risk and disaster. Its aim is twofold: * To provide a framework to facilitate the comparison between events that could or that have occurred. The aim of this ontology is to deal with all kinds of risks and disasters, whether they are naturally or human induced. * To facilitate the discussion between researchers from different disciplines using a graphical modeling language. This conceptual ontology is currently composed of four sub-systems (structure, dynamics, actors and representation) which allow the description of the facts, (the factual part permits to analyze the dynamics of the event and on what it has a bearing), and the representation of the event by the actors according to their conceptual framework. In this paper, we propose to use the factual part of this ontology to analyze Japan's triple disaster that occurred on March 11, 2011 and during the following days. Many papers, reports, videos and press articles were published, each one providing a wide variety of information. Some focused on the massive earthquake that triggered the devastating tsunami along the eastern coast of the Tohoku region, killing around 16000 people, while others mainly analyzed the nuclear crisis. The aim of the instantiation of the conceptual ontology is to synthesize in visual form all the information from various sources and to produce different kinds of analyses. These analyses can either be global or centered on one aspect of the cascading events, on a specific scale, date, period or a specific element of the observed system. For example, the ontology permits to point out that the difficulty facing the nuclear crisis is also partly due to the destruction of the road network. It also shows that if Japan's 2011 triple disaster occurred mainly in a country, the effects were not only local but also global. So, firstly, we propose to present the conceptual ontology of risk and disaster, secondly, a first instantiation carried out in May 2012, and finally, the advantages of this kind of approach to integrate new recent information about the cascading events that occurred in March 11, 2011, but also the recent problems (cooling system failures and radioactive water leaks) that occurred at the Fukushima Daiichi nuclear power plant showing that it is still not in stable shut-down.