The potential reasons for fire to start are numerous. However, fire needs three elements to start, and a chain reaction to keep it going – heat, oxygen, and fuel. In WSP we tend to focus on the aspects of heat and fuel because oxygen is usually ubiquitous. Heat, in many respects, is synonymous with ignition, and fuel is a function of the quantity and availability of combustible material. So, armed with that information it’s easy to conceptualize the common causes, and they follow naturally. There are sources of fire that we humans intend to create – cooking, heating, and smoking are obvious. There are others that, although necessary, we don’t necessarily intend to create – electrical sparking resulting from flicking a switch being the most common, but also, when it goes wrong, the heat, sparking, and flames that result from a failing electrical unit.