There are very few things on the fireground will kill you faster than underestimating the potential danger and arriving unprepared to a large commercial structure fire. History has repeatedly shown us that taking residential tactics and strategies into a commercial structure is extremely dangerous. Overaggressive tactics, improper hoseline selection, lack of SOPs, lack of understanding of the dangers of large buildings, overestimating the capabilities of the fire protection systems, not monitoring air supply, not knowing the fire load, and committing too deeply into warehouses with high rack storage are all common mistakes at big box fires. This class will take an in-depth look at the building construction features of modern, large commercial (big box) buildings including walls, roofs, mansards, and doors; the strengths and weaknesses of fire protection systems, what to expect from them, and how to use them to our advantage; every strategic, tactical, and command level fireground assignment and draw comparisons between residential and commercial fires; the different storage configurations that are commonly found in big box stores and how they affect our tactical decision making; and multiple significant fatal and near-miss fires that occurred across the country and evaluate what happened and how we can prevent it from reoccurring.