Two independent and very devastating earthquakes took place in epicentres of Pazarcık (Mw = 7.7) and Elbistan (Mw = 7.6) with an interval of 9 h in same day. Kahramanmaraş, the epicentres of the February 6, 2023 earthquakes, suffered major structural destruction and thousands of casualties, as a result of the disaster of century. A significant part of the residential units located on the Eastern Anatolian Fault System, one of the main tectonic belts of Türkiye, has a great seismic risk. Various degrees of destruction and damage have been observed in reinforced-concrete (R/C) buildings, which constitute the predominant urban building stock in Kahramanmaraş province and districts. The main earthquakes and the subsequent aftershocks negatively affected the damage level in R/C buildings having low earthquake performance. The structural damages in R/C buildings in Kahramanmaraş and districts based on field observations had been assessed within the context of earthquake and civil engineering. Incomplete or non-existent implementation of the principles of seismic-resistant building design during the construction and design phase and structural irregularities have been identified as the primary causes of the damage.