The investigation found the following factors to be instrumental in the destruction of the CTV Building: Intense horizontal ground shaking; Lack of ductility in the columns, making them brittle; Asymmetrical layout of the sheer walls, making the building twist during the earthquake, placing extra strain on the columns. These structural inadequacies also failed to meet the building standards in place when the CTV Building was completed in 1986. Other potential factors mentioned in the report include low concrete strength in some of the critical columns and possible interaction of columns and concrete spandrel panels on the external face of the building making the columns less flexible.
The Guardian has more details regarding the report, stating that this is the fourth report on collapsed buildings during that seismic event, but the first to identify inadequacies. Experts indicate that the non-compliant construction may set the stage for legal claims, as 115 of the 184 people that died in the quake were killed by the CTV Building’s collapse.