A characterization of materials was conducted in relation to the terminal, burst-type, failure of a PVRC pressure vessel of A212-A (now A515 Gr. 60) steel at 110 F. Materials were characterized with respect to chemical composition, tensile properties, fracture toughness - including Charpy-V and Tear Energies, Drop-Weight NDT, micrography and electron fractography.The initiation and growth of a 34-in. long fatigue crack was shown to be caused by mechanical aspects rather than material deficiencies and the plastic-instability burst, brittle run, and crack arrest were in complete accord with the Fracture Analysis Diagram.