Old mining tunnels were certainly a nightmare. But they did know how to ventilate them. They would sometimes dig a vertical shaft connected to a tunnel and set a fire in it. The fire would draw air in, and send smoke up. They could configure it so that it drew air from the working face, and sent it up and out.

Mines didn't have torches, they had small lamps. It was dark and hellish. Miners had short lives.