Mr. Reygadas said he was loading his truck just before going to lunch on Aug. 5 when he felt what seemed like an explosion. The pressure from falling rock “almost blew out” his ears, he said. The next sound he heard was miners shouting. Another miner, Yonny Barrios, 50, said “his ears felt like they were being sucked from one side to the other.”

The men began to search for their friends. It would take eight hours before they knew no one had died.

But whatever relief they felt was short-lived. Within hours, the men were faced with a fateful choice. There was a way out, through a ventilation shaft. But after discovering that the ladder there was too short, they knew all they could do was wait.

Two days later, a boulder rolled into the shaft, sealing it for good.

This is where the narrative goes silent. Like the three other miners interviewed  and those who have spoken to other media  Mr. Ojeda, a 24-year-veteran of the mines, refuses to go into great detail over what happened in the next two weeks, as men wilted in the heat and shrank, their tiny rations of tuna and crackers too meager to do much more than keep them alive.

The story picks up again on Day 17, when the rescuers’ drill bit pierced the roof of their refuge, starting the clock for their eventual freeing.

After that, the men say, there were many more light moments, despite the uncertainties of an unprecedented rescue plan. One day Mario Sepúlveda, one of the group’s most extroverted figures, donned a makeshift blonde wig and impersonated the millionaire philanthropist Leonardo Farkas offering to give the miners jobs, Mr. Reygadas said. (Mr. Farkas, in reality, gave each of the miners about $10,000.)