A notable fire occurred in the Avianca Building in Bogota, Colombia on July 23, 1973. After the fire the administrators of the Avianca Building and the Office of the Secretary of Public Works in Bogota requested that the structural designer, Domenico Parma, conduct an investigation to evaluate the structural integrity of the building and, if feasible, program its repair and reconstruction. The extensive investigation which followed substantiates the fact that engineers can now design concrete structures for fire endurance as readily as they design for static and dynamic loads. The techniques are known as the Rational Design Method. A visual examination of the structure revealed that columns and major framing members had sustained small enough damage to make it unnecessary to replace the structure, though one interior column near the fire origin had lost 20 percent of its gross area. Detailed examination of materials, structural components and the floor system in general revealed no significant reduction in concrete strength and no major cracking. In a structural response test, in which amplitude, frequency of vibration and damping characteristics of beams are measured, a general lack of stiffness was found in the precast-prestressed joist areas. It was then decided that only 30 percent of the floor was in need of replacement. Finally, load tests were made on specific areas of six floor. Results demonstrated that there was still sufficient load-carrying capacity, and the 30 percent replacement estimate of the floor was further revised to only 7 percent. On the basis of this investigation, the reasons for the remarkable behavior of the structure can be assigned to the following characteristics of design: the massiveness of the concrete members of the main structural system which, by absorbing large amounts of heat, maintained comparatively low temperatures in the strand and reinforcement; the use of grouted post-tensioned tendons, since the steel tubing and grout helped to protect the strands in the tendons; the good detailing and structural continuity of the precast elements in which no collapse occurred, although severe damage occurred in some areas.