Two major earthquakes occurred on the Eastern Anatolian Fault Line (EAF) on February 6, 2023, with an interval of nine hours. These earthquakes, measuring Mw 7.7 and Mw 7.6, were centered in the districts of Pazarcık and Elbistan in the province of Kahramanmaraş. They directly affected 11 provinces (Kahramanmaraş, Hatay, Adıyaman, Osmaniye, Gaziantep, Şanlıurfa, Malatya, Diyarbakır, Adana, Kilis, and Elazığ) in the Eastern and Southeastern Anatolia, caused significant loss of life and property. This study aims to present the field investigation and performance evaluation of engineering structures in the mentioned cities. The types of damages occurring in the reinforced concrete (RC) and masonry buildings, historical and industrial structures, bridges, and mosques were given in detail. According to the data of the Ministry of Treasury and Finance of Türkiye, it has been reported that the cost of these earthquakes is approximately 103.6 billion dollars, which corresponds to nine percent of Türkiye's national income expectation for 2023 and causes damage and losses of approximately six times more than the 1999 Marmara earthquake. In the areas affected by earthquakes, many of the errors determined by professionals from previous earthquakes still exist today.