On 30.10.2020, a Mw = 6.6 magnitude earthquake occurred at the offshore Aegean Sea, hitting the western coast of Turkey and Samos Island of Greece, causing loss of lives and properties. In the scope of this study, a site investigation was conducted at the earthquake-hit area of Izmir (Turkey), where 17 buildings (7 partially, 10 totally) were collapsed and many of them were heavily damaged. The impact of the Aegean Sea Earthquake on structures in the Izmir region, as observed during this site investigation is presented in this paper. The seismic vulnerabilities of structures, by referring to the observed typical damages caused by the earthquake, are discussed and preliminary analyses were also conducted in two reinforced concrete buildings to investigate the causes of seismic damages. The damage mechanisms are explained to highlight the causes and defects that led to failure of structures and recommendations are made for preventing such failures and life losses in the future. In additional to the structural damages, widespread non-structural damages which can make buildings non-functional are investigated. This paper also outlines seismological aspects of the region and characteristics of the recorded strong ground motion.