Abstract: A blast resistant shelter apparatus includes a framework having at least an upper metal rail. A plurality of metal panels each have a C-shaped cross-section defined by a central flat web and two channel arms on the opposite sides of the central flat web. The metal panels are vertically mounted within the framework in a side by side relationship to define a wall. Each panel includes an upper and a lower end plate. A metal interior wall cladding is connected to the panels and spans the channel arms of each panel to close the cross-sections of the panels to define an interior space of each panel. The upper metal rail and the upper end plate of each panel have aligned fill openings defined therethrough for introducing a particulate material such as sand into the interior space of the associated panel.