Over the past two decades, Poland has seen a transformative expansion in road infrastructure, including the construction of over 5,000 km of new highspeed multi-lane roads. This monumental investment involved numerous large-scale transportation structures, such as bridges, passageways, and culverts, designed to support the nation's evolving transport network. However, these developments posed significant challenges, particularly in the design and construction of large, complex structures with high massivity and complex restraints. A lack of expertise led to issues, the most prevalent being unanticipated cracking during construction or shortly after the structures entered service. This experience heightened national awareness of thermal cracking in reinforced concrete structures, a previously overlooked issue in structural design. This paper presents a forensic analysis of a passageway constructed as a semi-massive reinforced concrete frame, which experienced cracking during construction. The study examined the preventive measures and techniques implemented during the design and construction stages to mitigate the risk of thermal cracking and investigated the underlying causes of the observed damage.