Coupling device for forming a protective building system

A modular building removable coupling device for forming an explosion resistant, forced entry resistant, and/or ballistic resistant facility comprising:

• a. a first hollow square or rectangular tubing having a first hollow top side;
• b. a second hollow square or rectangular tubing having a second hollow top side;
• c. a sealing means disposed between the first hollow square or rectangular tubing and the second hollow square or rectangular tubing providing a weather resistant connection;
• d. a fastener centrally oriented to penetrate and connect the first hollow square or rectangular tubing to the second hollow square or rectangular tubing;
• e. a first roof plate secured to the first hollow square or rectangular tubing;
• f. a second roof plate secured to the second hollow square or rectangular tubing;
• g. a first side sealing tube non-removably secured to the first roof plate;
• and
• h. a second side sealing tube non-removably secured to the second roof plate, wherein the modular building removable coupling device connects a first explosion resistant, forced entry resistant, and/or ballistic resistant housing module to a second explosion resistant, forced entry resistant, and/or ballistic resistant housing module, forming the explosion resistant, forced entry resistant, and/or ballistic resistant facility.