When an existing structure shows some deficiency, example: cracks, permanent deformation, etc., Structural Investigation is needed to commense to assess the current status of the structure. Visual inspection is the primary source of information. From the direction of cracks or the permanent deflection, person that can tell the event that trigger the deficiency, current stability of structure, and other aspect that unique in every project are the data needed to study in orther to draw conclusion. Initial inspection nites can be assess to draw hypothesis which can be tested on the final inspection. Structural Investigation tells the current status of the structure.