While the Seattle-based retailer filed for the patent three years ago, it was issued and published more than a month ago. The filing details specifications for a underground network that could ...
Beneath parts of the Appalachian Mountains, thousands of mine shafts still descend deep into the earth. Some of these vertical passages drop more than 1,000 feet, connecting long corridors carved ...
Nashville's District Energy System is more than 50 years old and pumps chilled water and steam to more than 40 buildings through an underground tunnel network. Metro Council member Olivia Hill serves ...