## 6 Conclusions  
Some researchers have developed fragility and vulnerability functions for various building classes in different parts of the world, achieving promising results through open-access programs [5; 23; 49; 50; 24]. In the preceding sections, the probability of damage and loss was determined using a set of ground motion records characteristic of the region [45; 46]. The analysis was conducted on masonry houses in the city of Tijuana, BC, which, according to data from [35], represents over 432,000 housings. The open-source platform VMTK was employed, offering a viable option for determining fragility and vulnerability functions for various types of structures in the region and around the world. Before using it, it is essential to review its limitations and necessary features to ensure it can be easily adapted. The fragility models were developed following the cloud analysis method proposed by [39] and nonlinear time history analysis in equivalent SDOF oscillators. The derived fragility functions for low- and medium-rise masonry houses were compared for different seismic design levels. It was observed that the probability of damage decreases in low-rise houses for all damage states with moderate and high seismic design levels. Additionally, there is a 20% probability of reaching damage state D54 for low-rise houses with a low seismic design level, considering an expected value of 0.50 g of PGA. For medium-rise houses, there is no damage in DS2, DS3, and DS4 with a high seismic design level. Furthermore, there is a 16% probability of reaching damage state D54 for medium-rise houses with a low level of seismic design, considering an expected value of 0.50 g of SA (T = 0.5 s). In BC, over 50% of housings exhibit structural damage [35], stemming from a substantial portion of informal construction carried out over the years with low or nonexistent design standards, resulting in increased vulnerability of housings in the event of an earthquake. When deriving vulnerability functions, it was determined that for a low seismic design level, structures with 1-3 stories and 4-7 stories in height have a higher probability of loss indices, at 30% and 44%, respectively, for an expected value of 0.50 g of PGA and SA (T = 0.5 s). When comparing vulnerability functions for single-floor and two-floor houses with a low seismic design level, it is noteworthy that the results of this article reveal a significantly higher loss index, reaching 30%, surpassing that found by other authors. Similarly, for three- to five-floor houses, the loss index also significantly increases to 52%, positioning it above values obtained by other researchers. For single-floor houses with a moderate and high seismic design level, it can beobserved that the loss indices obtained in this study, which are 7% and 1.8%, respectively, are lower than those presented by [PERSON] et al. [37]. Conversely, these results show similarities with the values obtained by [PERSON] et al. [54]. In the case of two-floor houses with a moderate seismic design level, a notable similarity can beobserved between the results presented by [PERSON] et al. [54] and those of this study. On the other hand, for three- to five-floor houses with a moderate and high seismic design level, the values obtained in this study, which are 6% and 1%, respectively, are lower than those presented by [PERSON] et al. [37]. A comparison has been made between the vulnerability functions obtained in this article and those developed by other authors in different regions around the world, revealing significant discrepancies. These disparities could introduce greater uncertainty in damage and loss estimation in risk scenarios. In the specific case of the city of Tijuana, which is located in a high-seismic-activity zone, there areno available data regarding the damage caused by earthquakes prior to the generation of these vulnerability functions. Furthermore, there is no regulatory section addressing the specific use of vulnerability functions for masonry houses.