Every accident as a result of a hazard is preventable by breaking the accident chain before the last link. Breaking the chain is known as intervention, which is reactive, whereas reducing the potential for an accident chain at all is mitigation, which is proactive. An example of a reactive step is the creation of a collapse zone at a structure fire. An example of a proactive step is wearing personal protective equipment at a fire call.
The accident chain:
The environment such as weather or lighting
Human factors such as training or attitude
Equipment such as proper use and maintenance
Event the unsafe junction of the previous three links