Sandhogs

Walking Boss Morgan Curran and sandhogs of Local 147 tunnel beneath New York to complete the Croton Filtration Plant, a facility designed to help ensure the safety of the city's water supply.

Sandhogs conduct test blasts as construction of the first new subway tunnel expansion in 20 years begins; a foreman loses fingers in an accident.

The crew prepares for the project's next step of permanently joining two tunnels; the newly appointed foreman pushes his mole crew too hard; a solo blast in Manhattan.

Morale sinks to an all-time low as the tunnel-boring machine cuts through Croton's upper tunnel; Temporary Foreman Anthony Aviles' aggressive leadership style forces Walking Boss Morgan Curran to monitor the worrisome situation closely.

The Croton crew has little margin for error as they close in on their goal of mining 3,745 feet; a rookie sandhog working in Manhattan commits a gaffe known as "hanging a steel"; tricky double explosion; a man is hurt by a mammoth machine.

Walking Boss Morgan Curran and his gang work to complete the new tunnel's connection to the 118-year-old New Croton Aqueduct; while pouring concrete, clogs slow progress; injuries strike the crew; upgrading the Long Island Rail Road.