Hundreds of feet below one of the world's most famous cities, a different breed of men dig and blast their way through solid rock. These urban miners create the tunnels that ensure the survival of the city above. Meet Walking Boss Morgan Curran and the Sandhogs of Local 147. Under great pressure, these men work to complete the Croton Filtration Plant, a facility that will help ensure the safety of the city's water supply. In one tunnel they use the "Mole", an enormous tunnel-boring machine that relentlessly eats away at the rock. In the other tunnel, they're using large quantities of dynamite to blast their way through the earth. When a void develops along one of the tunnel walls, the hogs race to put up ring steel to prevent a cave in. And while the Brooklyn Bridge celebrates its 125th anniversary, the Sandhogs continue to toil below, preparing and detonating their next blast.
Discover a world under New York City where injury and death on the job are common occurrences. Watch as these workers toil underneath the streets of New York City just as they have for the past 150 years--they are an instrumental part of the development of the city. Their union, their identity and their culture have been forged in iron and steel, and it is a bond that is truly shared as a brotherhood.