This article addresses the precautions that can be taken in the design and installation of large-diameter steel conduits to prevent failure, and describes a massive failure of an 1800 mm pipeline in St. Louis, Missouri which resulted in an investigation to determine the cause of the failure. Tensile stress, temperature, impact load, weld defects, cold weather, construction faults, stress concentrations, and plate thickness are discussed as factors that contribute to the loss of ductility and promotion of brittle failure. The following are suggested as controls against brittle fracture: carbon/manganese composition of the pipe; deoxidation practices; and grain size of the steel. The author advises that immediate and thorough investigations of conduit failure help in defending against law suits or in preventing similar pipeline failures. Includes 6 references.