Toronto Tunnel

S1 E6: Host Mike Davidson is heading under one of the world's largest lakes for a multi-million-dollar tunnel-boring project. The crew's mission: to give Toronto's wastewater system a major upgrade, using a highly sophisticated machine capable of creating a tunnel with a diameter greater than a two-story house. But big machines often require big repairs. Witness the epic battles happening 260 feet below the Earth's surface as our hard-hat heroes battle challenge after challenge to keep this operation running on budget and on schedule.