The Error 404: 2. Walt
Class: Gen 4 Heavy Industry
Manufacturer: Chassis: US/T Systems, OS: US/T Industrial Research
…first sign of a tunnel collapse. The sensor arrays in the Bobs main instrument bus would detect the sudden change in air pressure and switch the Bob into P R O T E C T. The Bob would essentially star jump, spreading its arms high above its head and locking its legs to prepare to catch and brace the falling tunnel.
In P R O T E C T, the AI switches to low power mode, providing enough energy for basic thought functions while diverting the majority of output to run the carbon dioxide filters housed in the Bobs chest and, after 24 hours, to begin pumping oxygen into the collapsed tunnel.
When the tin mine at the Gaddaff Strait collapsed, six heavy mining Bobs saved the lives of over two hundred miners. It took almost three weeks to get the miners out. The recovery of the Bobs was deemed non-economically viable. So, they left ‘em down there. Buried. Still doing their jobs and probably still wondering when someone was going to come and pull them out.
Heavy industrial mining operations on both planets ceased centuries ago. Who knows how long Walt was under the ground before PA 404 dug him up?