This paper analyses the stress state in the walls of a closed steel profile caused by freezing water filling the interior of the profile. The study focuses on a specific case of two damaged girders, where the failure was attributed to freezing water trapped inside the upper chords of the girders. The analysis revealed that the resulting stresses exceeded the steel’s strength, leading to deformation and rupture of the upper chord profiles. The article describes the damage observed in the girders, including outward deformation of the walls and cracks along the bending edge. The presence of water and corrosion products inside the profiles was confirmed through inspections. Finite element calculations were performed to assess the pressure effects, showing that the tensile stresses in the corner of the profile exceeded the yield and tensile strength of the steel. The article concludes that damage caused by freezing water expansion is unpredictable and emphasises the importance of weld quality control in steel structures.