The 2004 Indian Ocean tsunami caused human casualties as well as various other types of damage because it struck an area that did not have physical defense structures such as breakwaters and seawalls and lacked nonstructural measures for tsunami awareness, such as warning systems and evacuation procedures. The widespread tsunami flooding of coastal lowlands triggered a chain of destruction to buildings; damage to social infrastructure, such as coastal roads, bridges, railways, and ports; erosion of coastal land; and destruction of ships, oil tanks, and automobiles. Such a complex disaster occurs when multiple hazard/disaster events with different characteristics are closely related. This study explains the actual situation in each region regarding wide-area complex disasters caused by earthquakes, large tsunamis, and other events as well as (1) hazards (predisposing factors), (2) impacts and damage, and (3) points that particularly increase the impact to express the relationship between each event in a flow. The results can be compared with the complex disaster flow chart of the 2011 Great East Japan Earthquake to deepen our understanding of the actual state of complex disasters.