King Coal by Upton Sinclair

There followed a night and then another day of torturing suspense. The fan came, but it had to be set up before anything could be done. As volumes of black smoke continued to pour from the shaft, the opening was made tight with a board and canvas cover; it was necessary, the bosses said, but to Hal it seemed the climax of horror. To seal up men and boys in a place of deadly gases!

There was something peculiarly torturing in the idea of men caught in a mine; they were directly under one's feet, yet it was impossible to get to them, to communicate with them in any way! The people on top yearned to them, and they, down below, yearned back. It was impossible to forget them for even a few minutes. People would become abstracted while they talked, and would stand staring into space; suddenly, in the midst of a crowd, a woman would bury her face in her hands and burst into tears, and then all the others would follow suit.