A modular building removable coupling device for forming an explosion resistant, forced entry resistant, and/or ballistic resistant facility. The coupling device can include two hollow square or rectangular tubings having hollow top sides, a sealing means disposed between the tubings, a fastener connecting the tubings, a roof plate secured to each tubing, and a roof cap disposed over the roof plates. The coupling device can include sealing tubes secured to inner sides of the roof cap. A plurality of explosion resistant, forced entry resistant, and/or ballistic resistant modules can be connected with a plurality of modular building removable coupling devices to form an explosion resistant, forced entry resistant, and/or ballistic resistant facility.