From past earthquakes, multi-story buildings with weak and/or open front wall lines creating a “soft-story” (i.e. buildings with tuck-under-parking) performed poorly and collapsed. The goal of the mandatory retrofit program, under Ordinance 183893 and Ordinance 184081, is to reduce structural deficiencies by the most economical and feasible method. Without proper strengthening, these vulnerable buildings may be subjected to structural failure during and/or after an earthquake.