The roof of a steel-framed industrial facility had partially collapsed in one location, and excessive deflections were reported at several additional locations. The owner attributed these conditions to the weight of ice and snow on the roof. Haag Engineers inspected this roof and noted extensive deterioration of the cold-formed steel roof purlins at the collapse from long-term roof leaks. Our failure and damage inspection also revealed non-standard connections of purlins where excessive deflection was reported. While the weight of snow on the roof triggered the collapse, the root cause was loss of structural capacity of roof purlins from long-term deterioration of building components due to roof leaks.