In 2017, the newly built parking garage at Eindhoven Airport collapsed. The disaster led to widespread research into composite concrete floors (breedplaatvloeren). It was quickly determined that a specific detail, where a positive moment has to be transferred from two precast floor slabs by coupling reinforcement in the in-situ compression layer, caused the collapse of the composite concrete floor. The force in the coupling reinforcement has to be transferred by the interface between the two concrete layers and the lattice girder reinforcement. Based on earlier research, a calculation model was developed to determine if the critical detail is sufficient in existing and new structures. Two failure mechanisms are described, failure of the interface and failure of the lattice girder. This research focuses on the failure behavior of the lattice girder in the composite concrete floor near a critical detail.