This article presents a synthesis of the Transportation Safety Board of Canada's (TSB) report on the brittle fracture of the hull of Lake Carling, and concludes with an overview of the TSB's safety concern on brittle fracture in ships, including ongoing initiatives at the International Maritime Organization. The TSB is an independent agency created to advance transportation safety through the investigation of occurrences in the marine, pipeline, rail and air modes of transportation. The majority of the world's civilian cargo vessels have side shells constructed with steel of unqualified toughness (grade A steel). In 2002 and 2003, respectively, samples of side shell steel from Lake Carling and a sister ship, Ziemia Gornoslaska (ex-Lake Charles), were made available to the TSB. Steel from both vessels had very poor fracture arrest toughness (low Charpy Vee Notch energies) at temperatures near 0°C. The relatively low fracture toughness of the side shell plate of Lake Carling, when exposed to near 0°C temperatures, allowed a pre-existing crack at frame 91 to grow to failure at a load well below the ultimate tensile strength of the material. Given the uncertainties and variability of fracture arrest toughness for some grade A and B steels, it would appear that residual risks for unstable brittle fracture are still present in vessels with hulls constructed with these steels, especially when operating in colder climates. Because there are no International Association of Classification Societies Ltd. Unified Requirements to use steel of qualified toughness in way of a vessel's side shell, the risk of brittle fracture can be perpetuated in a significant proportion of new buildings. Given the gravity of consequences of brittle fracture, the establishment of a standard is desirable. The standard should be rigorous enough to ensure that steel toughness would be adequate under all expected operating conditions such that a reasonable damage tolerance can be predicted and relied upon.