Abstract: Systems and methods are provided for a modular shelter that is suited for use as a safety chamber in an underground working environment. The shelter includes at least two wall units connected along a substantially sealed seam, a base unit that extends substantially throughout a floor plan of the shelter, and a roll cage that surrounds an outer extent of the shelter above the floor plan. The shelter may be configured to maintain a pressurized state in a closed condition. Each of the at least two wall units may share a substantially common shape and substantially common dimension, and may form a part of a wall, ceiling, and floor of the shelter. The shelter can also include various atmospheric control, circulation, and purge systems, and exterior and soft seal doors to assist in maintaining a livable atmosphere in the safety chamber.