Looks at some of the reasons why deep holes and tunnels are dug in the ground and in the oceans, including mining, waste disposal, and travel, discusses the challenges of deep digging or drilling, looks at how the tasks are accomplished, and considers the dangers of working underground.
The author, granted unrestricted access to the World Trade Center site in the wake of the September 11, 2001 terrorist attacks, describes the physical details of the collapse of the towers and the deconstruction of the ruins, and shares the stories of the workers who responded to the tragedy.
Describes underground areas including subways, bank vaults, and basement offices as well as the machines used to construct these places, dig tunnels, mine coal, and drill for oil.
Text and drawings describe the subways, sewers, building foundations, telephone and power systems, columns, cables, pipes, tunnels, and other underground elements of a large modern city.