We all depend on infrastructure for civilised living with the scale and sophistication of what we build ever increasing. Manifestly we all have a vested interest in construction being safe, and yet failures occur. Not infrequently these failures are catastrophic and accompanied by huge cost and occasional loss of life.Avoiding such tragedies is every engineer''s desire but how to do it is not straightforward. Nor is it straightforward to respond the question of: is this project safe? Nonetheless, progress can be made by laying down guidelines of what makes structures safe and by studying the pattern of past failures as a basis for predicting what might go wrong.This assists by drawing on the author''s considerable career experiences of observation, study and practice. The opening chapter describes the general challenges of making structures safe taking account of uncertainty and the consequence of failure, and it also describes the evolution of safety thinking which nowadays includes i