A structural component having an internal support structure extending between outer wall portions of the component with one or more compartments included within the support structure. The support structure has support members including internal walls positioned between and/or defined by the compartments. At least one support member connects between the outer wall portions of the component to enhance the structural integrity of the component. The structural component, including the internal support, are cast from a molten material, and in some cases the support members of the internal support structure are formed with a rectilinear configuration. In some cases the cast structural component is a container and the one or more compartments are configured to store a fluid, such as a gas or a liquid. One or more preforms can be used to form a container and may be retained or eliminated from the container after casting.