With increasing human dependence on electricity and increasing energy demand, electrical infrastructure has emerged to be one of the most critical services. On the other hand, climate-change driven extreme events progressively increase in frequency and intensity. This is one of the main reasons for making the power grid more resilient to extreme events during which uninterrupted power supply is crucial in keeping the consequences of the extreme event limited. The first step towards making the power grid more resilient is to evaluate the probabilities of failure for all assets at risk from the extreme events. Thus, this paper presents the a methodology to calibrate fragility curves. The strength of the proposed approach is its ability to calibrate the fragility curves utilizing limited data, which is the most common constraint in carrying out such analyses. This paper describes the calibration of transmission tower fragility curves for Puerto Rico utilizing only damage reports for hurricane Maria. That, combined with Puerto Rico’s wind modeling & geographic information system, this study also calibrates fragility curves for transmission towers made with four different construction materials.