Tongue and groove modular fire safe

A method of forming a modular fire safe, the method comprising the steps of:

• forming a base module having a plurality of base module cavities formed between an interior shell and an exterior shell, and one or more base module groove assemblies disposed within the plurality of base module cavities, each of the base module groove assemblies configured to form a base module first groove;
• forming one or more intermediate modules and positioning the one or more intermediate modules in a vertically stacked arrangement with the base module, the one or more intermediate modules having a plurality of intermediate module cavities formed between an interior shell and an exterior shell, one or more intermediate module groove assemblies disposed within an upper level of the plurality of intermediate module cavities and one or more intermediate module tongue assemblies disposed within a lower level of the plurality of intermediate module cavities, each of the intermediate module groove assemblies configured to form an intermediate module first groove, each of the intermediate module tongue assemblies having a first extension disposed in the plurality of intermediate module cavities and a second extension extending from the one or more intermediate modules;
• forming a top module and positioning the top module in a vertically stacked arrangement with an uppermost intermediate module, the top module having a plurality of top module cavities formed between an interior shell and an exterior shell and one or more top module tongue assemblies, each of the top module tongue assemblies having a first extension disposed in the plurality of top module cavities and a second extension extending from the one or more top modules;
• disposing the second extension of the one or more intermediate module tongue assemblies of the one or more intermediate modules in the base module first grooves of the one or more base module groove assemblies and the second extension of the one or more top module tongue assemblies in the intermediate module groove assemblies such that the base, intermediate and top modules form an assembled modular fire safe;
• and
• extending a plurality of retention members through the interior shells of the base module and the one or more intermediate modules to secure the one or more top module and one or more intermediate module tongue assemblies to the one or more base module and one or more intermediate module groove assemblies.