The purpose of this division is to promote the public welfare and safety by reducing the risk of death or injury that may result from the effects of earthquakes on existing concrete buildings. In the Northridge Earthquake, many concrete buildings constructed prior to the 1976 Los Angeles City Building Code provisions performed poorly and collapsed, causing loss of human life, personal injury and property damage. Similar loss of life, injury and property damage occurred in the Great Hanshin Earthquake, Mexico City Earthquake, and Christchurch New Zealand Earthquake due to the outdated building codes in those communities. The poor performance of these older concrete buildings is typically due to deficiencies in the lateral force resisting system (beams, columns and joints) that render the building incapable of sustaining gravity loads when the building is subjected to earthquake-induced lateral displacements. This division creates minimum standards to mitigate hazards from these structural deficiencies. Adherence to these minimum standards will improve the performance of these buildings during earthquakes and reduce, but not necessarily prevent, the loss of life, injury or earthquake-related damage.