Department of Labor)-backed mine safety mission – achieved a historic unmanned underground mine inspection at one of the US' largest underground room and pillar limestone operations in this comprehensive IM report. Using ten ADR Explora XL unmanned robots, a Rajant wireless Kinetic Mesh below-ground communication network, and PBE hardware and technology, a horizontal mobile infrastructure distance of 1.7 km was achieved. This allowed the unmanned robots to record high-definition video and LiDAR to create a virtual 3D mine model to assess the condition of the mine, for the deepest remote underground mine inspection in history. The inspection made it possible for MSHA to conclude within a very short time that it was safe to re-enter the operation and begin remediation efforts, which included allowing mine personnel back into the mine to re-establish power and communications, after which mining was able to recommence quickly at the site. The project, in many ways, is the ultimate example of necessity breeding innovation.