While security assessments of information systems are being increasingly performed with support of security modelling, safety assessments are still undertaken with traditional techniques such as Failure Mode and Effect Analysis (FMEA). As system modelling is becoming an increasingly important part of developing more safety critical systems, the safety field can benefit from security techniques that integrate system modelling and security aspects. This paper adapts an existing security modelling technique, Misuse Sequence Diagrams, to support failure analysis. The resulting technique, called Failure Sequence Diagrams, is used to support Failure Mode and Effect Analysis in an industrial setting. Based on the experiences, the authors suggest improvements both to traditional safety techniques and to security and safety modelling.