In our industry, fire is most often used to refine, purify or harden. The key is control and using temperatures appropriate for the specific processes. When fire is out of control, however, destruction ensues. Such was the case when fire destroyed a large home in rural Illinois this past winter. A study of the metal gusset plates in the rafters gives us some idea just how hot a housr fire gets and what it can do to the metal. Before discussing the metallurgical detail, however, looking at the cause of the fire may prevent another in the future.